Niacinamide is the biologically active form of niacin .

烟酰胺是烟酸的生物活性形式。

Dietary niacin and niacin formed within the body from the amino acid tryptophan are converted to niacinamide .

膳食烟酸和人体内形成的氨基酸色氨酸被转换为烟酰胺。