Plasma 25-hydroxyvitamin D (25(OH)D) concentrations in a group of thirtyeight nursing-home residents (age range 55-95 years) living in a sub-tropical climate (Brisbane, Australia) were less than 25 nmol/l in 50% of cases. The effects of endogenously and exogenously derived vitamin D have been studied over three months (April-June) using the following treatment groups: A, placebo; B, daily sun exposure; C, 18.8 nmol vitamin D/day and D, 56.3 nmol vitamin D/day. Exposure to ultra-violet radiation of group B patients was monitored by meter and palysulphone film. one month of treatment and groups B and C, respectively, after two months (P

Plasma 25 hydroxy Vitamin D (25 [OH]D) concentrations were studied in a group of 29 nursing home residents (age range 56 to 93 years) in a subtropical climate (Brisbane, Australia) before and after oral supplementation of 37.6 nmol of vitamin D per day over a 12‐month period. Eleven of the 29 subjects had pretreatment 25 ([OH]D) concentrations of less than 25 nmol/1. There was a significant rise in 25[OH]D concentrations from a baseline of 33.5 ±21.25 nmol/1 (mean±standard deviation) to 62.25±18 nmol/1 (P<0.001) while there was no significant change in calcium, phosphate and alkaline phosphatase concentrations during the 12 months. In this population, the daily supplement was efficacious in correcting vitamin D deficiency and in no case was there biochemical evidence of toxicity.