1. Clinical & Scientific Overview
Vitamin D3 / Cholecalciferol (Nutraceutical Profile) (TIP-MED-000625, Reference Code [SUP-01]) is classified under
Dietary Supplements & Nutraceuticals (FSSAI / ICMR-NIN) as a Clinical Nutrition & Nutraceutical Science • Fat-Soluble Secosteroid Pro-Hormone Micronutrient.
Within the Indian regulatory and compendial framework, it is governed under FSSAI Health Supplements and Nutraceutical Regulations, 2022 (RDA <=600 IU/day); Therapeutic high-dose 60,000 IU is a drug formulation..
FSSAI Licensed Health Supplement / Nutraceutical Formulations (RDA Compliant)
ICMR-NIN 2024 RDA: 600 IU/day (15 mcg) for adults, pregnancy, and lactation (400 IU/day in infants); Tolerable Upper Intake Level (UL): 4,000 IU/day (100 mcg). FSSAI Nutraceutical limit: up to 600 IU/day in general health supplements (60,000 IU granules/capsules are therapeutic Schedule H drugs, NOT daily nutraceuticals!).
Clinical Nutrition, ICMR-NIN RDA & FSSAI Nutraceutical Profile
Cholecalciferol (Vitamin D3)
Fat-Soluble Secosteroid Pro-Hormone Micronutrient
Cutaneous 7-dehydrocholesterol synthesis via UVB (290–315 nm), fatty fish, egg yolk, fortified milk/edible oil
ICMR-NIN 2024 Recommended Dietary Allowance (RDA) & Tolerable Upper Intake Limit (UL): ICMR-NIN 2024 RDA: 600 IU/day (15 mcg) for adults, pregnancy, and lactation (400 IU/day in infants); Tolerable Upper Intake Level (UL): 4,000 IU/day (100 mcg). FSSAI Nutraceutical limit: up to 600 IU/day in general health supplements (60,000 IU granules/capsules are therapeutic Schedule H drugs, NOT daily nutraceuticals!).
Deficiency Clinical Syndromes vs Chronic Excess / Hypervitaminosis Risks: Deficiency (<20 ng/mL 25-OH-D): Rickets in children, osteomalacia, secondary hyperparathyroidism, and proximal myopathy in adults. Excess (>100–150 ng/mL from chronic 60,000 IU daily/weekly misuse): Severe hypercalcaemia, hypercalciuria, nephrocalcinosis, acute kidney injury, and confusion.
Drug–Nutrient Chelation & Timing Interactions: Orlistat and cholestyramine reduce absorption; phenytoin, phenobarbitone, and carbamazepine accelerate hepatic 24-hydroxylase catabolism of 25(OH)D; hypercalcaemia from excess Vitamin D precipitates digoxin arrhythmia and thiazide milk-alkali syndrome.
FSSAI Health Supplement vs Therapeutic Drug Distinction: FSSAI Health Supplements and Nutraceutical Regulations, 2022 (RDA <=600 IU/day); Therapeutic high-dose 60,000 IU is a drug formulation.
3. Mechanism of Action & Pharmacodynamics
Hydroxylated in liver (CYP2R1) to 25(OH)D (calcifediol) and in renal proximal tubules (CYP27B1 / 1-alpha-hydroxylase) to active 1,25(OH)2D (calcitriol), which binds nuclear Vitamin D Receptors (VDR) to upregulate intestinal TRPV6 calcium channels and calbindin-D9k.
4. Therapeutic Indications & Evidence-Supported Uses
- Physiological & Biochemical Role: Hydroxylated in liver (CYP2R1) to 25(OH)D (calcifediol) and in renal proximal tubules (CYP27B1 / 1-alpha-hydroxylase) to active 1,25(OH)2D (calcitriol), which binds nuclear Vitamin D Receptors (VDR) to upregulate intestinal TRPV6 calcium channels and calbindin-D9k.
- Dietary Sources: Cutaneous 7-dehydrocholesterol synthesis via UVB (290–315 nm), fatty fish, egg yolk, fortified milk/edible oil
- ICMR-NIN RDA & Upper Limits: ICMR-NIN 2024 RDA: 600 IU/day (15 mcg) for adults, pregnancy, and lactation (400 IU/day in infants); Tolerable Upper Intake Level (UL): 4,000 IU/day (100 mcg). FSSAI Nutraceutical limit: up to 600 IU/day in general health supplements (60,000 IU granules/capsules are therapeutic Schedule H drugs, NOT daily nutraceuticals!).
5. Educational Dosage Context, Formulations & Administration
Educational Dosing & Regimen Summary: ICMR-NIN 2024 RDA: 600 IU/day (15 mcg) for adults, pregnancy, and lactation (400 IU/day in infants); Tolerable Upper Intake Level (UL): 4,000 IU/day (100 mcg). FSSAI Nutraceutical limit: up to 600 IU/day in general health supplements (60,000 IU granules/capsules are therapeutic Schedule H drugs, NOT daily nutraceuticals!).
Administration & Meal Timing: Orlistat and cholestyramine reduce absorption; phenytoin, phenobarbitone, and carbamazepine accelerate hepatic 24-hydroxylase catabolism of 25(OH)D; hypercalcaemia from excess Vitamin D precipitates digoxin arrhythmia and thiazide milk-alkali syndrome.
6. Pharmacokinetics, Metabolism & Renal/Hepatic Adjustment
Salt-form and meal-timing dependent gastrointestinal absorption; see bioavailability and drug-nutrient chelation notes (Orlistat and cholestyramine reduce absorption; phenytoin, phenobarbitone, and carbamazepine accelerate hepatic 24-hydroxylase catabolism of 25(OH)D; hypercalcaemia from excess Vitamin D precipitates digoxin arrhythmia and thiazide milk-alkali syndrome.).
Incorporated into cellular coenzyme pools, metalloproteins, or membrane phospholipids.
Caution with magnesium, potassium, calcium, vitamin D, and high-dose vitamin C/collagen (oxalate) in Chronic Kidney Disease.
Caution with fat-soluble vitamins and concentrated lipophilic extracts in hepatobiliary disease.
7. Contraindications, Precautions & High-Risk Warnings
- Supratherapeutic megadosing above the ICMR-NIN Tolerable Upper Intake Level (UL) without medical indication
- Deficiency (<20 ng/mL 25-OH-D): Rickets in children, osteomalacia, secondary hyperparathyroidism, and proximal myopathy in adults. Excess (>100–150 ng/mL from chronic 60,000 IU daily/weekly misuse): Severe hypercalcaemia, hypercalciuria, nephrocalcinosis, acute kidney injury, and confusion.
Key Clinical Precautions: Deficiency (<20 ng/mL 25-OH-D): Rickets in children, osteomalacia, secondary hyperparathyroidism, and proximal myopathy in adults. Excess (>100–150 ng/mL from chronic 60,000 IU daily/weekly misuse): Severe hypercalcaemia, hypercalciuria, nephrocalcinosis, acute kidney injury, and confusion.
8. Adverse Effects Profile
- Deficiency (<20 ng/mL 25-OH-D): Rickets in children, osteomalacia, secondary hyperparathyroidism, and proximal myopathy in adults. Excess (>100–150 ng/mL from chronic 60,000 IU daily/weekly misuse): Severe hypercalcaemia, hypercalciuria, nephrocalcinosis, acute kidney injury, and confusion.
- Deficiency (<20 ng/mL 25-OH-D): Rickets in children, osteomalacia, secondary hyperparathyroidism, and proximal myopathy in adults. Excess (>100–150 ng/mL from chronic 60,000 IU daily/weekly misuse): Severe hypercalcaemia, hypercalciuria, nephrocalcinosis, acute kidney injury, and confusion.
9. Major Drug–Drug, Drug–Food & Drug–Herb Interactions
- Orlistat and cholestyramine reduce absorption; phenytoin, phenobarbitone, and carbamazepine accelerate hepatic 24-hydroxylase catabolism of 25(OH)D; hypercalcaemia from excess Vitamin D precipitates digoxin arrhythmia and thiazide milk-alkali syndrome.
10. Clinical Monitoring, Patient Counselling & Storage
Clinical & Laboratory Monitoring: Verify whether the patient requires physiological nutritional maintenance (<=1 RDA under FSSAI) or high-dose therapeutic deficiency correction (Schedule H/medical supervision), and check for multi-supplement stacking.
Pharmacist Patient Counselling Points:
- Orlistat and cholestyramine reduce absorption; phenytoin, phenobarbitone, and carbamazepine accelerate hepatic 24-hydroxylase catabolism of 25(OH)D; hypercalcaemia from excess Vitamin D precipitates digoxin arrhythmia and thiazide milk-alkali syndrome.
- Check all multivitamin and wellness labels to avoid accidentally doubling up on fat-soluble vitamins (A, D, E, K), iron, or zinc.
- Health supplements support normal physiological nutrition and are NOT intended to diagnose, treat, cure, or prevent disease under Section 22 of the FSS Act, 2006.
Storage, Stability & Dispensing Safeguards: Store in a cool, dry place below 25°C away from moisture and direct sunlight; verify FSSAI License Number and Veg/Non-Veg symbol on packaging.
11. Visual Pharmacology & Mechanism Diagram (svg-v339-01-adme-12-step-journey)
12. Authoritative References, Regulatory Sources & Editorial Disclaimer
Primary Compendial & Guideline Reference: ICMR-NIN (National Institute of Nutrition) Nutrient Requirements and Recommended Dietary Allowances (RDA) for Indians (2020/2024); FSSAI (Health Supplements, Nutraceuticals, Food for Special Dietary Use, Food for Special Medical Purpose, Functional Food and Novel Food) Regulations, 2022.
Official Verification Portals: ICMR-National Institute of Nutrition (NIN) — Dietary Guidelines & Nutrient Requirements for Indians • FSSAI — Food Safety and Standards (Health Supplements and Nutraceuticals) Regulations
Last Medically & Pharmaceutically Reviewed: 2026-11-10 • Verification Status: VERIFIED_EDUCATIONAL_CONTENT
Educational & Clinical Disclaimer: This reference profile is published solely for pharmacy education, academic study, and professional clinical reference. It does not substitute for patient-specific clinical judgement, qualified specialist oncology/medical supervision, or official CDSCO/IP prescribing information. Never self-medicate with prescription, Schedule H/H1/X, NDPS, or oncology medicines.