Can You Take Methylcobalamin and Vitamin B3 Together?

Dose or timing may matter

The short answer

High-dose niacin (B3) may impair methylcobalamin metabolism by competing for methyl groups in the methylation cycle. Niacin clearance requires SAMe-dependent methylation, which draws from the same methyl pool that methylcobalamin feeds into.

How to arrange timing

Ensure adequate methylcobalamin intake when using high-dose niacin therapy.

Reference

Reference noted for this combination: Bogan KL, Brenner C. Nicotinic acid, nicotinamide, and nicotinamide riboside: a molecular evaluation. Annu Rev Nutr. 2008;28:115-130

Important context

Whether supplements suit you together also depends on dose, product formulation, health conditions, and medication use. Ask a doctor or pharmacist first if you take medication, are pregnant or breastfeeding, or have a chronic condition.