[Low 25-hydroxy-vitamin D (25-OH-D) plasma levels in pathology (author's transl)].

Between october 1976 and march 1978, 160 patients with low 25-OH-D plasma levels were observed (25-OH-D less than 7 ng/ml). In this population, a high frequency of asthenia, anorexia, vertebral demineralization were noticed. Mean plasma level of calcium was significantly lower than controls. Mean plasma level of alkalin phosphatases was significantly higher than controls. These patients presented a varied pathology. These diseases were probably responsible for the low 25-OH-D plasma level. The mechanisms were varying, but anorexia and sun exposure defect were likely the main cause of the low 25-OH-D plasma level.