Vitamin D insufficiency: Definition, diagnosis and management

Severe vitamin D deficiency can be defined as the dose of vitamin D or serum 250HD concentrations needed to prevent nutritional rickets or osteomalacia. There is large international consensus that these diseases can be prevented by 400 IU of vitamin Did and 250HD above 30 nmol/l (12 ng/ml). Vitamin D deficiency can also accelerate the risk of fractures and probably also of falls in elderly subjects but there is no consensus on the required daily doses or minimal 250HD threshold for these endpoints. The majority of experts consider 800 IU/d and serum 250HD above 50 nmolil (20 ng/ml) as sufficient, with a minority opinion aiming for 75 nmol/l or even higher. For other extra-skeletal endpoints, no hard evidence is available to define whether or not this is causally related to vitamin D status. Therefore, for these endpoints no minimal dosage or 250HD threshold can be defined. (C) 2018 Published by Elsevier Ltd.