Vitamin D status of two groups of elderly in Oslo: living in old people's homes and living in own homes.
Vitamin D status of two groups of elderly was determined by measuring serum concentrations of 25-hydroxyvitamin D3 (25-OHD), and dietary and supplemental vitamin D intake. Group A consisted of 35 women (mean age 86 years), and 21 men (mean age 80 years) living in 5 different homes for elderly. Group B consisted of free-living elderly, 24 women (mean age 76 years) and 7 men (mean age 79 years). There was no or little seasonal variation in serum 25-OHD concentrations in either group. Of those who did not use vitamin D supplements, 83% of the women and 77% of the men in group A, and 40% of the women and none of the men in group B had 25-OHD concentrations below 20 ng/ml in the winter serum samples. Of the 49 individuals who used supplements, only 2 had values below 20 ng/ml. In the institutionalized elderly, 14-15 micrograms vitamin D per day as supplement was associated with a mean increase in 25-OHD concentration in winter serum samples of 25 ng/ml. Dietary intakes of vitamin D were low for both groups, especially for the women (less than 3 micrograms). It is concluded that elderly Norwegians, in particular those living in institutions, ought to improve their vitamin D status by increasing their exposure to sunshine and by including more oily fish in their diet. If this is difficult to achieve, vitamin D supplement (10 micrograms/day) should be used.