In the developed nations, the incidence of vitamin deficiencies have decreased. However, still considerable numbers of person with latent vitamin deficiencies exist in these countries. The insufficiency of vitamin is not so severe as to cause obvious symptoms, but can bring about various complaints due to what is called latent vitamin deficiencies. In Japan, the incidence of latent thiamin deficiency is regarded as rather high (about 30~40%), latent deficiency of ascorbic acid is about 15%. For other vitamins, latent hypovitaminosis is absent or very rare among healthy people.