Severe vitamin D deficiency in Auckland

To study the presentation of severe vitamin D deficiency in Auckland and to determine if appropriate therapy was given.

Retrospective review of records of patients with very low plasma 25 hydroxyvitamin D concentrations (< or = 12.5 nmol/L or 5 micrograms/L).

Fifty cases were identified over a two year period. 28 subjects had recognised risk factors for vitamin D deficiency (such as gastrointestinal disease or greatly reduced food intake). The majority of the other 22 subjects were elderly residents of rest homes or private hospitals. Low body weight and reduced mobility were common features of both groups. Increased plasma alkaline phosphatase activity and hypocalcaemia were the most frequent biochemical findings. Appropriate treatment with high dose calciferol had been given to only 28% of the subjects.

Severe vitamin D deficiency does occur in Auckland despite its low latitude. Low body weight, reduced mobility and lack of sun exposure are particular risk factors. Appropriate therapy is cheap, safe and effective but many patients with severe vitamin D deficiency are being managed suboptimally.