1. Clinical & Scientific Overview
Methylcobalamin / Vitamin B12 (Nutraceutical Profile) (TIP-MED-000626, Reference Code [SUP-02]) is classified under
Dietary Supplements & Nutraceuticals (FSSAI / ICMR-NIN) as a Clinical Nutrition & Nutraceutical Science • Water-Soluble Cobalt-Corrinoid Coenzyme Vitamin.
Within the Indian regulatory and compendial framework, it is governed under FSSAI Health Supplements & Nutraceutical Regulations, 2022..
FSSAI Licensed Health Supplement / Nutraceutical Formulations (RDA Compliant)
ICMR-NIN 2024 RDA: 2.2 mcg/day (adults), 2.45 mcg/day (pregnancy), 3.2 mcg/day (lactation); FSSAI Nutraceutical permitted level: up to 1 RDA in health supplements (500–1,500 mcg therapeutic strengths are drug formulations).
Clinical Nutrition, ICMR-NIN RDA & FSSAI Nutraceutical Profile
Methylcobalamin / Cyanocobalamin
Water-Soluble Cobalt-Corrinoid Coenzyme Vitamin
Exclusively animal-derived foods (dairy, eggs, fish, poultry, meat) and fortified nutritional yeast/cereals (high prevalence of deficiency in Indian vegetarian diets)
ICMR-NIN 2024 Recommended Dietary Allowance (RDA) & Tolerable Upper Intake Limit (UL): ICMR-NIN 2024 RDA: 2.2 mcg/day (adults), 2.45 mcg/day (pregnancy), 3.2 mcg/day (lactation); FSSAI Nutraceutical permitted level: up to 1 RDA in health supplements (500–1,500 mcg therapeutic strengths are drug formulations).
Deficiency Clinical Syndromes vs Chronic Excess / Hypervitaminosis Risks: Deficiency: Megaloblastic macrocytic anaemia, hyperhomocysteinaemia, glossitis, and Subacute Combined Degeneration of the spinal cord (dorsal column and corticospinal tract demyelination). Note: High-dose folic acid masks B12 megaloblastic anaemia while allowing irreversible neurological damage to progress!
Drug–Nutrient Chelation & Timing Interactions: Long-term Metformin (>4 months) reduces ileal calcium-dependent cubilin receptor uptake of Intrinsic Factor-B12 complex (take oral calcium carbonate or monitor B12 annually in metformin users); Proton Pump Inhibitors (omeprazole, pantoprazole) and H2 blockers impair gastric acid cleavage of B12 from food proteins.
FSSAI Health Supplement vs Therapeutic Drug Distinction: FSSAI Health Supplements & Nutraceutical Regulations, 2022.
3. Mechanism of Action & Pharmacodynamics
Essential coenzyme for cytoplasmic Methionine Synthase (converting homocysteine + 5-methyl-THF into methionine + THF for myelin methylation and DNA synthesis) and mitochondrial Methylmalonyl-CoA Mutase (converting L-methylmalonyl-CoA to succinyl-CoA).
4. Therapeutic Indications & Evidence-Supported Uses
- Physiological & Biochemical Role: Essential coenzyme for cytoplasmic Methionine Synthase (converting homocysteine + 5-methyl-THF into methionine + THF for myelin methylation and DNA synthesis) and mitochondrial Methylmalonyl-CoA Mutase (converting L-methylmalonyl-CoA to succinyl-CoA).
- Dietary Sources: Exclusively animal-derived foods (dairy, eggs, fish, poultry, meat) and fortified nutritional yeast/cereals (high prevalence of deficiency in Indian vegetarian diets)
- ICMR-NIN RDA & Upper Limits: ICMR-NIN 2024 RDA: 2.2 mcg/day (adults), 2.45 mcg/day (pregnancy), 3.2 mcg/day (lactation); FSSAI Nutraceutical permitted level: up to 1 RDA in health supplements (500–1,500 mcg therapeutic strengths are drug formulations).
5. Educational Dosage Context, Formulations & Administration
Educational Dosing & Regimen Summary: ICMR-NIN 2024 RDA: 2.2 mcg/day (adults), 2.45 mcg/day (pregnancy), 3.2 mcg/day (lactation); FSSAI Nutraceutical permitted level: up to 1 RDA in health supplements (500–1,500 mcg therapeutic strengths are drug formulations).
Administration & Meal Timing: Long-term Metformin (>4 months) reduces ileal calcium-dependent cubilin receptor uptake of Intrinsic Factor-B12 complex (take oral calcium carbonate or monitor B12 annually in metformin users); Proton Pump Inhibitors (omeprazole, pantoprazole) and H2 blockers impair gastric acid cleavage of B12 from food proteins.
6. Pharmacokinetics, Metabolism & Renal/Hepatic Adjustment
Salt-form and meal-timing dependent gastrointestinal absorption; see bioavailability and drug-nutrient chelation notes (Long-term Metformin (>4 months) reduces ileal calcium-dependent cubilin receptor uptake of Intrinsic Factor-B12 complex (take oral calcium carbonate or monitor B12 annually in metformin users); Proton Pump Inhibitors (omeprazole, pantoprazole) and H2 blockers impair gastric acid cleavage of B12 from food proteins.).
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: Megaloblastic macrocytic anaemia, hyperhomocysteinaemia, glossitis, and Subacute Combined Degeneration of the spinal cord (dorsal column and corticospinal tract demyelination). Note: High-dose folic acid masks B12 megaloblastic anaemia while allowing irreversible neurological damage to progress!
Key Clinical Precautions: Deficiency: Megaloblastic macrocytic anaemia, hyperhomocysteinaemia, glossitis, and Subacute Combined Degeneration of the spinal cord (dorsal column and corticospinal tract demyelination). Note: High-dose folic acid masks B12 megaloblastic anaemia while allowing irreversible neurological damage to progress!
8. Adverse Effects Profile
- Deficiency: Megaloblastic macrocytic anaemia, hyperhomocysteinaemia, glossitis, and Subacute Combined Degeneration of the spinal cord (dorsal column and corticospinal tract demyelination). Note: High-dose folic acid masks B12 megaloblastic anaemia while allowing irreversible neurological damage to progress!
- Deficiency: Megaloblastic macrocytic anaemia, hyperhomocysteinaemia, glossitis, and Subacute Combined Degeneration of the spinal cord (dorsal column and corticospinal tract demyelination). Note: High-dose folic acid masks B12 megaloblastic anaemia while allowing irreversible neurological damage to progress!
9. Major Drug–Drug, Drug–Food & Drug–Herb Interactions
- Long-term Metformin (>4 months) reduces ileal calcium-dependent cubilin receptor uptake of Intrinsic Factor-B12 complex (take oral calcium carbonate or monitor B12 annually in metformin users); Proton Pump Inhibitors (omeprazole, pantoprazole) and H2 blockers impair gastric acid cleavage of B12 from food proteins.
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:
- Long-term Metformin (>4 months) reduces ileal calcium-dependent cubilin receptor uptake of Intrinsic Factor-B12 complex (take oral calcium carbonate or monitor B12 annually in metformin users); Proton Pump Inhibitors (omeprazole, pantoprazole) and H2 blockers impair gastric acid cleavage of B12 from food proteins.
- 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.