Nutritional factors that regulate on the conversion of L-tryptophan to niacin

Niacin is biosynthesized from L-tryptophan. As a lot of L-tryptophan exists in the body, the pathway is very important because niacin can be efficiently supplied even when the body emergently needs niacin. Therefore, it is very important to know factors affecting the conversion ratio of L-tryptophan to niacin. The conversion ratio is decreased with increasing dietary protein levels. In the effects of fat, feeding of diets containing unsaturated fatty acids increased the conversion ratio, while feeding of diets saturated fatty acids did not. In the effects of carbohydrate, the conversion ratio was higher in diets containing starch than in diets containing sucrose.