vitamin reference
Reference image
(vitamin · DailyMed)
Registered Kenya · PPB

EUVITAN KUKU FORMULA

OXYTETRACYCLINE HCL, VITAMIN D3, VITAMIN E, VITAMIN A, VITAMIN K3 AND CHOLINE CHLORIDE

What it does

Cholecalciferol is a form of vitamin D that helps maintain healthy bones and teeth.

Commonly used for: vitamin D deficiency, rickets, osteomalacia

Read more in plain English ↓

Plain-language summary for general understanding - not medical advice. Always follow your pharmacist/doctor.

Ask about this medicine

Answers come only from this medicine's registration record, BNF monograph and interaction data - not medical advice.

Hard to find? We help patients in Kenya source rare medicines. We don't sell or dispense medicines - licensed pharmacies do.

Source this medicine

Registration & product details

Registration no.
V95/648
Registration date
-
Expiry date
-
Status
Registered
Active ingredient
OXYTETRACYCLINE HCL, VITAMIN D3, VITAMIN E, VITAMIN A, VITAMIN K3 AND CHOLINE CHLORIDE
Strength
-
Pack size
-
Therapeutic class
-
ATC class (WHO)
A11CC - Vitamin D and analogues
RxNorm RxCUI
2418
Manufacturer / MAH
Laboratory & Allied
Applicant / LTR
-
Country of origin
LOCAL
Manufacturer location
National Park East gate road, Lab and, Mombasa Road, Nairobi, Kenya

Source: Pharmacy and Poisons Board · fetched 2026-01-28 21:34:07 · updated 2026-07-20 11:08:25

Drug Interactions

15
Check interactions

Pharmacodynamic Warnings

Oxytetracycline appears in TABLE 1: Drugs that cause hepatotoxicity

Severe (3)

Tetracyclines - decreases absorption

Strontium is predicted to decrease the absorption of tetracyclines. Avoid. Theoretical Sucralfate

Severe Theoretical

Vitamin - increases risk of vitamin a toxicity

TretinoinispredictedtoincreasetheriskofvitaminAtoxicity whengivenwithvitaminA.Avoid.rStudy Ribavirin e

Severe Study

Vitamin - increases risk of vitamin a toxicity

Retinoids(tretinoin)arepredictedtoincreasetheriskof vitaminAtoxicitywhengivenwithvitaminA.Avoid.r Study VitaminDsubstances . . . . . alfacalcidol.calcipotri..ol calcitriol colecalciferol ergocalcifero

Severe Study

Moderate (4)

Lithium - increases risk of lithium toxicity

Tetracyclines are predicted to increase the risk of lithium toxicity when given with lithium. Avoid or adjust dose.

Moderate Anecdotal

Tetracyclines - decreases concentration

Fosphenytoin is predicted to decrease the concentration of tetracyclines (doxycycline). Adjust dose.

Moderate Theoretical

Tetracyclines - decreases exposure

Rifampicin modestly decreases the exposure to tetracyclines (doxycycline). Adjust dose.

Moderate Study

Vitamin - increases risk of toxicity

Retinoids (bexarotene) are predicted to increase the risk of toxicity when given with vitamin A. Adjust dose.

Moderate Theoretical

Unknown (8)

Tetracyclines - decreases exposure

Mitotane is predicted to decrease the exposure to tetracyclines (eravacycline). Adjust eravacycline dose, p. 625.

Unknown Study

Tetracyclines - decreases exposure

Rifampicin is predicted to decrease the exposure to tetracyclines (eravacycline). Adjust eravacycline dose, p. 625.

Unknown Study

Tetracyclines - decreases exposure

St John's wort is predicted to decrease the exposure to tetracyclines (eravacycline). Adjust eravacycline dose, p. 625.

Unknown Theoretical

Tetracyclines - decreases absorption

Oralzincispredictedtodecreasetheabsorptionof tetracyclines.Separateadministrationby2to3hours. oTheoretical https://www.facebook.c (Books-Courses-Medic

Unknown Theoretical

Vitamin - decreases effects

Carbamazepine is predicted to decrease the effects of vitamin D substances.

Unknown Study

Vitamin - increases exposure

Cobicistat is predicted to increase the exposure to vitamin D substances (paricalcitol).

Unknown Study

Vitamin - increases exposure

Idelalisib is predicted to increase the exposure to vitamin D substances (paricalcitol).

Unknown Study

Vitamin - increases exposure

Clarithromycin is predicted to increase the exposure to vitamin D substances (paricalcitol).

Unknown Study

Data from BNF 85 (British National Formulary). This is not a substitute for professional medical advice. Matched via: class

Disclaimer: This information is sourced from Pharmacy and Poisons Board (Kenya). Always consult a qualified healthcare professional before using any medication.

About cholecalciferol

Cholecalciferol is a form of vitamin D that helps maintain healthy bones and teeth.

What it treats

  • vitamin D deficiency
  • rickets
  • osteomalacia

How it works

Cholecalciferol helps your body absorb calcium and phosphorus, which are essential for strong bones.

Who it's for

It is suitable for individuals who need to boost their vitamin D levels, especially those with limited sun exposure.

AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.

About choline

Choline is a nutrient important for various bodily functions, including brain health and liver function.

What it treats

  • supporting brain health
  • helping with liver function

How it works

Choline helps produce important substances in the body, like phospholipids, which are essential for cell membranes.

Who it's for

Choline can be beneficial for people needing support for cognitive function and liver health.

AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.

About oxytetracycline

Oxytetracycline is an antibiotic used to treat various bacterial infections.

What it treats

  • bacterial infections
  • acne
  • respiratory infections
  • urinary tract infections

How it works

It works by stopping the growth of bacteria, helping to eliminate the infection.

Who it's for

It is for adults and children over the age of 12 who have specific bacterial infections.

Drug class

Tetracyclines

Cautions

  • • Avoid use with other medications that can harm the liver.

AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.

About retinol

Retinol is a form of vitamin A that helps improve skin health and appearance.

What it treats

  • acne
  • wrinkles
  • dry skin
  • psoriasis

How it works

Retinol promotes skin cell turnover, helping to clear up acne and reduce signs of aging.

Who it's for

Adults looking to improve their skin quality or treat specific skin conditions.

AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.

About tocopherol

Tocopherol is a form of vitamin E, an antioxidant that helps protect cells from damage.

What it treats

  • skin health
  • antioxidant support
  • nutritional supplement

How it works

It helps protect your body from harmful substances by neutralizing free radicals.

Who it's for

It is suitable for people looking to support their overall health and skin condition.

AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.

About vitamin

Vitamins are essential nutrients that support various bodily functions and overall health.

What it treats

  • nutritional deficiency
  • general health maintenance

How it works

Vitamins support normal bodily functions, including metabolism, immune function, and cell repair.

Who it's for

Anyone needing to improve their nutrient intake or maintain good health.

AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.

Clinical monograph: Oxytetracycline

BNF-referenced

Oxytetracycline is a broad-spectrum antibiotic belonging to the tetracycline class. It is effective against a variety of bacterial infections, including those caused by Chlamydia, Rickettsia, and Mycoplasma. This medication works by inhibiting protein synthesis in bacteria, making it a vital option in treating susceptible infections. Its use is cautioned in pediatric populations due to potential adverse effects on bone and dental development.

Indications

  • Bacterial infections (e.g. Chlamydia, Rickettsia, Mycoplasma)
  • Acne
  • Prophylaxis of asymptomatic meningococcal carrier state (not recommended)

Dosage

Adults: For adult patients, the typical dosage of oxytetracycline for susceptible infections is 100 mg twice daily for 5 days. For other conditions, such as acne, the dosage may be 500 mg twice daily, usually for a duration of 6 to 12 weeks, with the possibility of repeating the course intermittently.

Mechanism of action

Oxytetracycline exerts its antibacterial effects by binding to the 30S ribosomal subunit of bacteria, inhibiting the binding of aminoacyl-tRNA to the mRNA-ribosome complex. This action prevents the synthesis of proteins essential for bacterial growth and replication, leading to the bacteriostatic effect of the drug.

Pharmacodynamics

The pharmacodynamics of oxytetracycline involve its ability to inhibit bacterial protein synthesis, which is critical for the growth and reproduction of bacteria. The drug demonstrates a broad spectrum of activity against both Gram-positive and Gram-negative organisms, as well as some atypical pathogens. Its effectiveness can be influenced by the presence of tetracycline resistance mechanisms in certain bacterial strains.

Pharmacokinetics

Oxytetracycline is well absorbed from the gastrointestinal tract, with peak plasma concentrations occurring approximately 1-2 hours after oral administration. It has a relatively long half-life of about 8-10 hours, allowing for twice-daily dosing. The drug is widely distributed in body tissues and fluids, including the liver, kidneys, and lungs, but is less effective in central nervous system infections due to limited penetration. It is primarily excreted via urine, and dosage adjustments may be necessary in patients with renal impairment.

Contra-indications

  • Children under 12 years due to deposition in growing bone and teeth, causing staining and occasionally dental hypoplasia

Adverse effects

  • Gastrointestinal disturbances
  • Photosensitivity
  • Dental discoloration
  • Hepatotoxicity
  • Renal impairment
  • Skin reactions including rash and urticaria
  • Ataxia
  • Hearing impairment
  • Colitis
  • Systemic lupus erythematosus exacerbation

Interactions

  • Antacids and supplements containing calcium, magnesium, or iron may reduce absorption
  • Oral contraceptives may be less effective
  • Other tetracyclines
  • Warfarin (may increase anticoagulant effect)

Precautions

  • Use with caution in patients with renal impairment
  • Monitor for hepatic toxicity in long-term use
  • Patients should be advised to avoid excessive sunlight exposure
  • Discontinue if systemic lupus erythematosus develops or worsens

Pregnancy

Oxytetracycline is contraindicated during pregnancy due to potential harm to fetal development, particularly affecting bone and dental health.

Breast-feeding

Use with caution; oxytetracycline is excreted in breast milk and may affect the infant's dental health.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

  • Oxytetracycline 250 mg tablets
  • Oxytetracycline oral suspension
  • Oxytetracycline oral solution
BNF 85 (British National Formulary) p.646 BNF for Children 2019-2020 p.389 PubChem / pathway

AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.

Clinical monograph: cholecalciferol

BNF-referenced

Cholecalciferol, also known as vitamin D3, is a fat-soluble vitamin essential for maintaining normal serum calcium and phosphorus levels. It is naturally synthesized in the skin upon exposure to sunlight and can also be obtained from certain dietary sources. Cholecalciferol is crucial for bone health, as it aids in the absorption of calcium and phosphorus from the gut and supports bone mineralization. Deficiency in vitamin D can lead to conditions such as rickets in children and osteomalacia in adults, characterized by weakened bones and skeletal deformities.

Indications

  • Vitamin D deficiency
  • Rickets
  • Osteomalacia
  • Osteoporosis
  • Hypoparathyroidism

Dosage

Adults: The usual adult dose for vitamin D deficiency is 800 to 2000 IU daily, depending on the severity of deficiency and clinical condition. Higher doses may be used under medical supervision.

Mechanism of action

Cholecalciferol is converted to its active forms, 25-hydroxyvitamin D in the liver and 1,25-dihydroxyvitamin D in the kidneys. These metabolites enhance the intestinal absorption of calcium and phosphorus, increase serum calcium levels, and mobilize these minerals from bone. This process is regulated by parathyroid hormone, which influences calcium and phosphate metabolism, particularly in the kidneys.

Pharmacodynamics

The pharmacodynamics of cholecalciferol involve its conversion to active metabolites that play a significant role in calcium and phosphorus homeostasis. The metabolites facilitate intestinal absorption of these minerals, promote bone mineralization, and influence renal reabsorption. The onset of action occurs within 10 to 24 hours following administration, as metabolic activation is required for its biological effects.

Pharmacokinetics

Cholecalciferol is absorbed in the gastrointestinal tract, and its absorption is enhanced by the presence of dietary fats. It is transported in the bloodstream bound to vitamin D-binding protein. Once in the liver, it undergoes hydroxylation to form 25-hydroxyvitamin D, which is further converted in the kidneys to the active form, 1,25-dihydroxyvitamin D. The elimination half-life of cholecalciferol varies, typically spanning several days, and it is primarily excreted in bile and urine.

Adverse effects

  • Hypercalcemia
  • Hypercalciuria
  • Nausea
  • Vomiting
  • Constipation
  • Weakness
  • Fatigue

Interactions

  • May enhance the effects of thiazide diuretics, leading to increased risk of hypercalcemia
  • Anticonvulsants may increase metabolism of vitamin D, leading to reduced effectiveness
  • Cholestyramine may reduce absorption of vitamin D

Precautions

  • Monitor serum calcium levels in patients with renal impairment
  • Caution in patients with a history of hypercalcemia or hyperparathyroidism
  • Use with caution in patients taking other medications that affect calcium metabolism

Pregnancy

Cholecalciferol can be used during pregnancy if indicated, as vitamin D is essential for fetal bone development.

Breast-feeding

Cholecalciferol is excreted in breast milk, but is generally considered safe during breastfeeding.

Storage

Store in a cool, dry place, away from light. Keep out of reach of children.

Formulations

  • Capsules
  • Tablets
  • Liquid formulations

AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.

Clinical monograph: choline

BNF-referenced

Choline is an essential nutrient that plays a critical role in various biological processes, particularly in the maintenance of cell membrane integrity, neurotransmitter synthesis, and lipid metabolism. It is a precursor of acetylcholine, a neurotransmitter vital for nerve conduction and cognitive function. Choline also contributes to the synthesis of phosphatidylcholine and sphingomyelin, important phospholipids in cellular membranes. Inadequate choline intake can lead to several health issues, including liver dysfunction and neurological disorders.

Indications

  • Choline deficiency
  • Support in liver function
  • Neurological health, including cognitive function
  • Fat metabolism disorders

Dosage

Children: Refer to the BNF for Children for specific dosing guidelines.

Adults: Refer to the BNF for specific dosing guidelines.

Mechanism of action

Choline is a major component of phosphatidylcholine, which is essential for maintaining cell membrane integrity, facilitating information flow, and intracellular communication. It is involved in the synthesis of acetylcholine, a key neurotransmitter in the central nervous system. Choline deficiency can lead to apoptosis by affecting cell membrane composition and increasing ceramide levels, which activates apoptotic pathways. Additionally, choline is a precursor to betaine, which helps regulate homocysteine levels, thus reducing cardiovascular risks.

Pharmacodynamics

Choline is crucial for proper nerve conduction in the central nervous system as it is a precursor for acetylcholine. It supports liver function, gallbladder regulation, and lipid metabolism. Adequate choline levels are associated with the prevention of excessive fat accumulation in the liver and may mitigate conditions such as Parkinsonism and tardive dyskinesia. Deficiencies can lead to serious health problems, including liver dysfunction and stunted growth.

Pharmacokinetics

Choline is absorbed in the intestines and distributed throughout the body, where it is utilized in various metabolic pathways. The liver plays a central role in choline metabolism, converting it into phosphatidylcholine and other metabolites. The half-life and excretion pathways of choline are not well defined but are influenced by dietary intake, physiological state, and individual metabolism.

Interactions

  • corticosteroids+cholinesalicylate: Unknown (decreases concentration)

Pregnancy

Choline is generally considered safe during pregnancy, as it is essential for fetal development, particularly for brain development and function. However, it is important to adhere to recommended dietary allowances.

Breast-feeding

Choline is important during breastfeeding as it supports infant brain development. Adequate intake is recommended for nursing mothers.

Storage

Store in a cool, dry place, away from direct sunlight and moisture. Keep out of reach of children.

AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.

Clinical monograph: retinol

BNF-referenced

Retinol, also known as Vitamin A, is a fat-soluble vitamin essential for various physiological functions including vision, epithelial differentiation, growth, and immune function. It is critical for the synthesis of rhodopsin, a photoreceptor protein in the retina that enables vision in low-light conditions. Retinol acts through nuclear retinoid receptors to influence gene expression and is vital for maintaining healthy skin and mucous membranes.

Indications

  • Vitamin A deficiency
  • Night blindness
  • Impaired wound healing
  • Epithelial disorders

Dosage

Children: Refer to BNF for Children for specific paediatric dosing information.

Adults: Refer to BNF for specific adult dosing information.

Mechanism of action

Retinol is converted in the retina to 11-cis-retinal, which is crucial for the conversion of light into neural signals necessary for vision. It binds to opsin in rhodopsin, facilitating the isomerization to all-trans-retinal upon exposure to light, thus triggering visual signaling. Additionally, retinol interacts with retinoic acid receptors (RARs) and retinoid-X receptors (RXRs) as transcription factors, modulating gene expression related to cellular differentiation and growth.

Pharmacodynamics

Vitamin A is effective in treating Vitamin A deficiency, which can lead to vision impairment and other health issues. It plays a critical role in various biological processes including vision, cellular differentiation, reproduction, and immune system function. Its deficiency can cause symptoms such as night blindness and impaired wound healing, while adequate levels support growth and development.

Pharmacokinetics

Retinol is absorbed from the gastrointestinal tract and stored in the liver, where it can be mobilized as needed. It undergoes metabolism primarily in the liver, where it is converted to retinal and retinoic acid, the active forms of Vitamin A. The elimination half-life varies, but retinol is generally excreted in urine and bile. The bioavailability can be affected by dietary fat intake.

Adverse effects

  • Nausea
  • Vomiting
  • Headache
  • Dizziness
  • Fatigue
  • Irritability
  • Dry skin
  • Peeling of skin
  • Itching
  • Blurred vision

Precautions

  • Use with caution in patients with liver disease due to potential hepatotoxicity.
  • Monitor for signs of vitamin A toxicity, especially in patients on high doses or prolonged therapy.
  • Caution in patients with a history of alcohol abuse, as it may exacerbate liver conditions.

Pregnancy

Retinol should be used with caution during pregnancy due to the risk of teratogenic effects. High doses of vitamin A can lead to fetal malformations.

Breast-feeding

Retinol is generally considered safe during breastfeeding, but excessive intake should be avoided to prevent potential adverse effects on the infant.

Storage

Store in a cool, dry place away from light. Keep out of reach of children.

Formulations

  • Capsules
  • Tablets
  • Oral solutions
  • Topical preparations

AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.

Clinical monograph: tocopherol

BNF-referenced

Tocopherol, commonly known as vitamin E, is a fat-soluble antioxidant that plays a critical role in protecting cell membranes from oxidative stress. It is primarily found in various dietary sources, including nuts, seeds, and green leafy vegetables. Tocopherol acts by donating hydrogen atoms to free radicals, thereby neutralizing their harmful effects and preventing cellular damage.

Indications

  • Prevention of vitamin E deficiency
  • Antioxidant therapy
  • Support in conditions related to oxidative stress

Dosage

Children: Refer to BNF for Children for specific dosage guidelines.

Adults: Refer to BNF for specific dosage guidelines.

Mechanism of action

Tocopherol acts as a radical scavenger, primarily functioning as an antioxidant for lipid bilayers. It donates hydrogen atoms to free radicals, trapping them and preventing cellular damage. Its effectiveness is influenced by its location within the membrane and its interaction with cytosolic reductants like ascorbate. Tocopherol can trap multiple radicals, including alkyl and peroxy radicals.

Pharmacodynamics

The antioxidant properties of tocopherol lead to significant pharmacodynamic effects, including the inhibition of cell death through modulation of protein kinase C (PKC). Tocopherol also exhibits anti-inflammatory effects, which can be attributed to its influence on cytokines, prostaglandins, prostanoids, and thromboxanes. These interactions may contribute to its protective effects in various pathological conditions.

Pharmacokinetics

Tocopherol is absorbed in the intestines and its bioavailability can be influenced by dietary fat intake. It is transported in the plasma primarily bound to lipoproteins. Tocopherol is stored in adipose tissue and the liver, and its elimination occurs through bile and urine. The half-life of tocopherol can vary depending on the individual's nutritional status and other factors.

Pregnancy

Tocopherol is generally considered safe during pregnancy, but it is advisable to consult a healthcare provider before use.

Breast-feeding

Tocopherol is excreted in breast milk, and while it is considered safe, a healthcare provider should be consulted for specific recommendations.

Storage

Store in a cool, dry place away from direct sunlight.

AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.

Clinical monograph: vitamin

BNF-referenced

Vitamins are organic compounds that are essential for various metabolic processes in the body. They play crucial roles in maintaining health, supporting the immune system, and promoting growth and development. Different vitamins have specific functions, and they are required in varying amounts depending on age, sex, and physiological conditions.

Indications

  • Vitamin deficiency syndromes (e.g., scurvy for vitamin C deficiency, rickets for vitamin D deficiency)
  • Support for immune function
  • Antioxidant support
  • Bone health maintenance
  • Vision health
  • Energy metabolism support

Dosage

Children: Refer to the BNF for Children for specific vitamin dosing guidelines, which depend on age and nutritional requirements.

Adults: Refer to specific vitamin guidelines as dosage varies significantly depending on the type of vitamin and individual needs.

Mechanism of action

Vitamins function primarily as coenzymes or precursors for coenzymes in enzymatic reactions. For instance, B vitamins are involved in energy metabolism, while vitamins A, C, D, E, and K support various physiological functions including vision, antioxidant activity, calcium regulation, and blood clotting. Each vitamin has a unique mechanism of action based on its structure and role in the body.

Pharmacodynamics

Vitamins exert their effects at the cellular level, influencing metabolic pathways, gene expression, and immune responses. For example, vitamin D regulates calcium and phosphate homeostasis, while vitamin A is crucial for vision and immune function. Deficiencies in vitamins can lead to a range of disorders, highlighting their importance in maintaining health.

Pharmacokinetics

The pharmacokinetics of vitamins vary widely. Fat-soluble vitamins (A, D, E, and K) are stored in liver and adipose tissues and can be released into circulation as needed. Water-soluble vitamins (B-complex and C) are not stored and must be consumed regularly, with excess amounts excreted in urine. Absorption rates, half-lives, and distribution can also differ based on the specific vitamin and individual metabolic factors.

Interactions

  • tretinoin+vitamin: Severe (increases risk of vitamin toxicity)
  • retinoids+vitamin: Severe (increases risk of vitamin toxicity)
  • retinoids+vitamin: Moderate (increases risk of toxicity)
  • carbamazepine+vitamin: Unknown (decreases effects)
  • cobicistat+vitamin: Unknown (increases exposure)
  • vitamin D substances+digoxin: Unknown (increases risk of toxicity)
  • idelalisib+vitamin: Unknown (increases exposure)
  • clarithromycin+vitamin: Unknown (increases exposure)

Pregnancy

Consult healthcare professional before use. Vitamin supplementation during pregnancy should be carefully managed to avoid hypervitaminosis.

Breast-feeding

Consult healthcare professional before use. Some vitamins can pass into breast milk and may affect the infant.

Storage

Store in a cool, dry place, away from direct sunlight. Ensure it is kept out of reach of children.

Formulations

  • {'name': 'Vitamin A', 'form': 'Capsule', 'strength': '10000 IU'}
  • {'name': 'Vitamin D', 'form': 'Tablet', 'strength': '1000 IU'}
  • {'name': 'Vitamin E', 'form': 'Softgel', 'strength': '400 IU'}

AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.

Molecular reference: Oxytetracycline

PubChem CID 54675779

Molecular formula: C22H24N2O9

Source: PubChem (NCBI) · pathways from PathBank, Reactome, WikiPathways & PharmGKB.

Molecular reference: cholecalciferol

PubChem CID 5280795

Molecular formula: C27H44O

Mechanism of action

Most individuals naturally generate adequate amounts of vitamin D through ordinary dietary intake of vitamin D (in some foods like eggs, fish, and cheese) and natural photochemical conversion of the vitamin D3 precursor 7-dehydrocholesterol in the skin via exposure to sunlight. Conversely, vitamin D deficiency can often occur from a combination of insufficient exposure to sunlight, inadequate dietary intake of vitamin D, genetic defects with endogenous vitamin D receptor, or even severe liver or kidney disease. Such deficiency is known for resulting in conditions like rickets or osteomalacia, all of which reflect inadequate mineralization of bone, enhanced compensatory skeletal demineralization, resultant decreased calcium ion blood concentrations, and increases in the production and secretion of parathyroid hormone. Increases in parathyroid hormone stimulate the mobilization of skeletal calcium and the renal excretion of phosphorus. This enhanced mobilization of skeletal calcium leads towards porotic bone conditions. Ordinarily, while vitamin D3 is made naturally via photochemical processes in the skin, both itself and vitamin D2 can be found in various food and pharmaceutical sources as dietary supplements. The principal biological function of vitamin D is the maintenance of normal levels of serum calcium and phosphorus in the bloodstream by enhancing the efficacy of the small intestine to absorb these minerals from the diet. At the liver, vitamin D3 or D2 is hydroxylated to 25-hydroxyvitamin D and then finally to the primary active metabolite 1,25-dihydroxyvitamin D in the kidney via further hydroxylation. This final metabolite binds to endogenous vitamin d receptors, which results in a variety of regulatory roles - including maintaining calcium balance, the regulation of parathyroid hormone, the promotion of the renal reabsorption of calcium, increased intestinal absorption of calcium and phosphorus, and increased calcium and phosphorus mobilization of calcium and phosphorus from bone to plasma to maintain balanced levels of each in bone and the plasma. In particular, calcitriol interacts with vitamin D receptors in the small intestine to enhance the efficiency of intestinal calcium and phosphorous absorption from about 10-15% to 30-40% and 60% increased to 80%, respectively. Furthermore, calcitriol binds with vitamin D receptors in osteoblasts to stimulate a receptor activator of nuclear factor kB ligand (or RANKL) which subsequently interacts with receptor activator of nuclear factor kB (NFkB) on immature preosteoclasts, causing them to become mature bone-resorbing osteoclasts. Such mature osteoclasts ultimately function in removing calcium and phosphorus from bone to maintain blood calcium and phosphorus levels. Moreover, calcitriol also stimulates calcium reabsorption from the glomerular filtrate in the kidneys. Additionally, it is believed that when calcitriol binds with nuclear vitamin D receptors, that this bound complex itself binds to retinoic acid X receptor (RXR) to generate a heterodimeric complex that consequently binds to specific nucleotide sequences in the DNA called vitamin D response elements. When bound, various transcription factors attach to this complex, resulting in either up or down-regulation of the associated gene's activity. It is thought that there may be as much as 200 to 2000 genes that possess vitamin D response elements or that are influenced indirectly to control a multitude of genes across the genome. It is in this way that cholecalciferol is believed to function in regulating gene transcription associated with cancer risk, autoimmune disorders, and cardiovascular disease linked to vitamin D deficiency. In fact, there has been some research to suggest calcitriol may also be able to prevent malignancies by inducing cellular maturation and inducing apoptosis and inhibiting angiogenesis, exhibit anti-inflammatory effects by inhibiting foam cell formation and promoting angiogenesis in en

Pharmacodynamics

The in vivo synthesis of the predominant two biologically active metabolites of vitamin D occurs in two steps. The first hydroxylation of vitamin D3 cholecalciferol (or D2) occurs in the liver to yield 25-hydroxyvitamin D while the second hydroxylation happens in the kidneys to give 1, 25-dihydroxyvitamin D. These vitamin D metabolites subsequently facilitate the active absorption of calcium and phosphorus in the small intestine, serving to increase serum calcium and phosphate levels sufficiently to allow bone mineralization. Conversely, these vitamin D metabolites also assist in mobilizing calcium and phosphate from bone and likely increase the reabsorption of calcium and perhaps also of phosphate via the renal tubules. There exists a period of 10 to 24 hours between the administration of cholecalciferol and the initiation of its action in the body due to the necessity of synthesis of the active vitamin D metabolites in the liver and kidneys. It is parathyroid hormone that is responsible for the regulation of such metabolism at the level of the kidneys.

Source: PubChem (NCBI) · pathways from PathBank, Reactome, WikiPathways & PharmGKB.

Molecular reference: choline

PubChem CID 305

Molecular formula: C5H14NO+

Mechanism of action

Choline is a major part of the polar head group of phosphatidylcholine. Phosphatidylcholine's role in the maintenance of cell membrane integrity is vital to all of the basic biological processes: information flow, intracellular communication and bioenergetics. Inadequate choline intake would negatively affect all these processes. Choline is also a major part of another membrane phospholipid, sphingomyelin, also important for the maintenance of cell structure and function. It is noteworthy and not surprising that choline deficiency in cell culture causes apoptosis or programmed cell death. This appears to be due to abnormalities in cell membrane phosphatidylcholine content and an increase in ceramide, a precursor, as well as a metabolite, of sphingomyelin. Ceramide accumulation, which is caused by choline deficiency, appears to activate Caspase, a type of enzyme that mediates apoptosis. Betaine or trimethylglycine is derived from choline via an oxidation reaction. Betaine is one of the factors that maintains low levels of homocysteine by resynthesizing L-methionine from homocysteine. Elevated homocysteine levels are a significant risk factor for atherosclerosis, as well as other cardiovascular and neurological disorders. Acetylcholine is one of the major neurotransmitters and requires choline for its synthesis. Adequate acetylcholine levels in the brain are believed to be protective against certain types of dementia, including Alzheimer's disease.

Pharmacodynamics

This compound is needed for good nerve conduction throughout the CNS (central nervous system) as it is a precursor to acetylcholine (ACh). Choline is also needed for gallbladder regulation, liver function and lecithin (a key lipid) formation. Choline also aids in fat and cholesterol metabolism and prevents excessive fat build up in the liver. Choline has been used to mitigate the effects of Parkinsonism and tardive dyskinesia. Choline deficiencies may result in excessive build-up of fat in the liver, high blood pressure, gastric ulcers, kidney and liver dysfunction and stunted growth.

Source: PubChem (NCBI) · pathways from PathBank, Reactome, WikiPathways & PharmGKB.

Molecular reference: retinol

PubChem CID 445354

Molecular formula: C20H30O

Mechanism of action

Vision:Vitamin A (all-<i>trans</i> retinol) is converted in the retina to the 11-<i>cis</i>-isomer of retinaldehyde or 11-<i>cis</i>-retinal. 11-<i>cis</i>-retinal functions in the retina in the transduction of light into the neural signals necessary for vision. 11-<i>cis</i>-retinal, while attached to opsin in rhodopsin is isomerized to all-<i>trans</i>-retinal by light. This is the event that triggers the nerve impulse to the brain which allows for the perception of light. All-<i>trans</i>-retinal is then released from opsin and reduced to all-<i>trans</i>-retinol. All-<i>trans</i>-retinol is isomerized to 11-<i>cis</i>-retinol in the dark, and then oxidized to 11-<i>cis</i>-retinal. 11-<i>cis</i>-retinal recombines with opsin to re-form rhodopsin. Night blindness or defective vision at low illumination results from a failure to re-synthesize 11-<i>cis</i> retinal rapidly. Epithelial differentiation: The role of Vitamin A in epithelial differentiation, as well as in other physiological processes, involves the binding of Vitamin A to two families of nuclear retinoid receptors (retinoic acid receptors, RARs; and retinoid-X receptors, RXRs). These receptors function as ligand-activated transcription factors that modulate gene transcription. When there is not enough Vitamin A to bind these receptors, natural cell differentiation and growth are interrupted. Topical vitamin A can reverse the impairment of wound healing seen in patients receiving corticosteroids, perhaps by restoring the normal inflammatory reaction in the wound. The possibility has been suggested that systemic vitamin A could inhibit the anti-inflammatory effect of systemic corticosteroids. Retinol arrested proliferation of cultured neuroblastoma cells at concentrations of 50 um. A correlation existed between inhibition of growth and inhibition of ornithine decarboxylase in both neuroblastoma cells and glioma cells with retinol. In rats exptl-hypervitaminosis A has been shown ... to produce severe damage of the retina, mainly in the pigment epithelium according to electron microscopy. Alcohol dehydrogenase activity was shown to disappear in the pigment epithelium and visual cells ... . /The authors/ have shown that in an experimental cell culture system consisting of carcinogen-treated 10T1/2 cells, both retinoids and all dietary carotenoids examined can reversibly inhibit neoplastic transformation in the post-initiation phase of carcinogenesis. This activity strongly correlates with their ability to increase gap junctional intercellular communication by up-regulating the expression of the gene CX43 (connexin43). Connexins comprise the structural unit of gap junctions, organelles which allow direct transfer of signals, nutrients and waste products between contacting cells. CX43 is the most widely expressed member of the gap junction family of genes, and we have demonstrated that its expression is strongly down-regulated in human cancers and in several premalignant conditions. When several human tumour cell lines were genetically engineered to conditionally express CX43 under the influence of a tetracycline promoter, their neoplastic phenotype was strongly attenuated. Specifically, induced cells were inhibited from growing in an anchorage-independent manner and, additionally, growth as xenografts in immunocompromised animals was also strongly attenuated. Growth inhibition in suspension was associated both with increased G(1) cell-cycle arrest and with increased apoptosis. /The authors/ propose a model whereby junctional communication allows the transfer of growth inhibitory signals from normal to neoplastic cells and that retinoids and carotenoids, by increasing signal transfer, act to prevent cancer.

Pharmacodynamics

Vitamin A is effective for the treatment of Vitamin A deficiency. Vitamin A refers to a group of fat-soluble substances that are structurally related to and possess the biological activity of the parent substance of the group called all-<i>trans</i> retinol or retinol. Vitamin A plays vital roles in vision, epithelial differentiation, growth, reproduction, pattern formation during embryogenesis, bone development, hematopoiesis and brain development. It is also important for the maintenance of the proper functioning of the immune system.

Source: PubChem (NCBI) · pathways from PathBank, Reactome, WikiPathways & PharmGKB.

Molecular reference: tocopherol

PubChem CID 14986

Molecular formula: C28H48O2

Mechanism of action

Tocopherol acts as a radical scavenger. It mainly acts as an antioxidant for lipid bilayers. Tocopherol's functions depend on the H-atom donating ability, location, and movement within the membrane, as well as the efficiency in the radical recycling by some cytosolic reductants such as ascorbate. Tocopherol actions are related to the trap of radicals, and it has been shown that even in the absence of substituents in the ortho-positions, tocopherol can trap more than two radicals. The type of radicals available for tocopherol are alkyl and peroxy.

Pharmacodynamics

The antioxidant effects of tocopherol can be translated into different changes at the pharmacodynamic level. In vitro studies have shown that this antioxidant activity can produce modification in protein kinase C (PKC) which will later be translated into an inhibition of cell death. Some other derivate effects are the anti-inflammatory properties of tocopherol which can be related to the modulation of cytokines or prostaglandins, prostanoids and thromboxanes.

Source: PubChem (NCBI) · pathways from PathBank, Reactome, WikiPathways & PharmGKB.

Molecular reference: vitamin

PubChem CID 266052

Molecular formula: C14H15NO7

Source: PubChem (NCBI) · pathways from PathBank, Reactome, WikiPathways & PharmGKB.

This drug in other countries

The same active ingredient registered across other registries we cover - including different brands.