Relevance of a borderline vitamin deficiency in relation to the question of vitamin requirement.

A definition is given for the terms of latent and borderline vitamin deficiency, and the vitamin requirement and optimal vitamin supply, respectively, are discussed in relation to these two terms. The upper limit of the latent vitamin deficiency status can be used to define the optimal intake of vitamins, whereas the lower limit indicates the minimum requirement. The impact on health of a latent vitamin deficiency lies in the risk of falling into a manifest vitamin deficiency during sudden stress, whereas, in borderline vitamin deficiency status, some health functions are affected so that a problem of public health may arise and countermeasures should be taken.