Low vitamin D status: definition, prevalence, consequences, and correction.

Low vitamin D status is extremely common worldwide due to low dietary intake and low skin production. Suboptimal vitamin D status contributes to many conditions, including osteomalacia/rickets, osteoporosis, falls, and fractures. It is possible or even likely that low vitamin D status increases risk for a multitude of other conditions. Although consensus does not exist, it appears that circulating 25(OH)D concentrations greater than 30 to 32 ng/mL are needed for optimal health. To achieve this, daily intakes of at least 1000 IU of D3 daily are required, and it is probable that substantially higher amounts are required to achieve such values on a population basis. It seems premature to recommend widespread screening for 25(OH)D measurement. Targeted measurement in those at increased risk for vitamin D deficiency and those most likely to have a prompt positive response to supplementation is appropriate. Widespread optimization of vitamin D status likely will lead to prevention of many diseases with attendant reduction of morbidity, mortality, and expense.