Endocrine Abstracts

Vitamin-D binding protein (VDBP) is the main reservoir of circulating vitamin D and its metabolites in blood. VDBP deficiency leads to a benign phenotype of undetectable vitamin D in the blood without remarkable effects in the calcium and bone metabolism if dietary vitamin D is sufficient ((Safadi et al 1999, Banerjee et al 2021)). This paradoxical phenotype is probably explained by the free-hormone hypothesis, which suggest that only the unbound vitamin D fr...