Niacinamide, also known as nicotinamide, is the amide form of Vitamin B3 (Niacin). It is a water-soluble vitamin that functions as a precursor to the essential coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), which are critical for hundreds of enzymatic reactions in cellular metabolism, energy production, DNA repair, and cellular signaling. Unlike niacin, it does not cause cutaneous flushing. In the Indian context, it is widely used for dermatological conditions and as a nutritional supplement.
Adult: **Nutritional/Pellagra:** 250-500mg daily in divided doses. **Dermatological (Acne/Pigmentation):** 250-500mg twice daily. Maximum recommended therapeutic dose is 1500mg/day.
Note: Administer orally with or after food to minimize potential gastrointestinal discomfort. Tablet should be swallowed whole with a glass of water. For dermatological benefits, consistent daily use for at least 8-12 weeks is required.
Niacinamide's primary mechanism is as a precursor for the synthesis of NAD+ and NADP+. These coenzymes are vital for redox reactions in glycolysis, fatty acid oxidation, and the electron transport chain. It modulates inflammatory pathways, inhibits poly(ADP-ribose) polymerase (PARP) and sirtuins at high doses, reduces sebum production, inhibits melanosome transfer to keratinocytes, and improves skin barrier function by increasing ceramide synthesis.
Pregnancy: Category A (Australian categorization). Considered safe. It is a water-soluble vitamin and excess is excreted. Recommended dietary allowance (RDA) is increased in pregnancy. Therapeutic doses (250-500mg) are likely safe but should be used only if clearly indicated.
Driving: No known effects. Dizziness or fatigue are rare but if experienced, caution is advised.
| Isoniazid | Isoniazid is a Vitamin B3 antagonist and can induce deficiency. Niacinamide supplementation may be required. | Moderate |
| 6-Mercaptopurine/Azathioprine | Niacinamide may inhibit thiopurine methyltransferase, potentially increasing toxicity of these drugs. | Moderate |
| Antidiabetic Drugs (Insulin, Sulfonylureas) | High-dose niacinamide (>>1g/day) may impair glucose tolerance and reduce drug efficacy. Monitor blood glucose. | Moderate |
| Allopurinol | Potential additive effect in lowering uric acid, but high-dose niacinamide may increase uric acid. Monitor. | Minor |
Same composition (Niacinamide (250mg)), different brands: