Vitamin D deficiency in adults

Vitamin D deficiency is a common condition that affects a significant number of Australians. Vitamin D is important in the maintenance of bone health, and deficiency leads to osteomalacia and contributes to fragility fractures. Deficiency has also been implicated in a wide variety of extra-skeletal conditions. Vitamin D can be easily assessed in patients by measuring serum 25-hydroxyvitamin D. Replacement of vitamin D needs to be tailored for each patient and depends on the severity of the deficiency. Toxicity is unlikely with vitamin D when it is administered as cholecalciferol as it has a wide safety window. The adequacy of replacement should be monitored and in cases of persistently low concentrations, malabsorptive conditions (especially coeliac disease) should be excluded.