Vitamin B3

Forms

niacin, niacinamide, nicotinic acid, inositol hexasuccinate

Sources

Liver, red meat, chicken, fish, eggs, legumes, green leafy vegetables, mushrooms, sunflower seeds and nuts.

Interactions

Griseofulvin

• Mechanism: Vitamin B3 increases the solubility and bioavailability of griseofulvin in the body, and in combination with vitamin B3, the dose of griseofulvin can be reduced.

• Recommendation: People taking griseofulvin should avoid taking vitamin B3 in combination, as it may increase griseofulvin levels and cause toxic effects unless the dose of griseofulvin is reduced.

Statins, especially lovastatin and pravastatin

• Mechanism: Vitamin B3 and statins are used to lower blood cholesterol. One of their common side effects is myopathy (muscle pain) and rhabdomyolysis, which increase the likelihood of this complication if taken together.

• Recommendation: Although concomitant use of vitamin B3 derivatives with statins such as lovastatin and pravastatin increases therapeutic efficacy and further reduces blood cholesterol, due to the aggravation of muscle complication, concomitant use of vitamin B3 in people treated with statins must be prescribed by a doctor.

Oral contraceptives

• Mechanism: Taking oral contraceptives reduces vitamin B3 in the body by reducing vitamin B6.

• Recommendation: In women taking oral contraceptives, daily intake of at least 10-25 mg of vitamin B3 (niacin), through B-complex or multivitamin, is necessary to prevent vitamin B3 reduction due to oral contraceptives.

Sulfonylureas (glibenclamide, gliclazide, chlorpropamide, etc.)

• Mechanism: Taking supplements containing vitamin B3 will increase blood sugar and reduce the effectiveness of sulfonylureas.

• Recommendation: People who use sulfonylureas should avoid taking vitamin B3 derivatives at the same time, but if it is necessary, the dose of sulfonylureas should be increased.