Nutritional status in a healthy elderly population: vitamin D

Abstract

The vitamin D status in a group of healthy free-living elderly people was determined by measuring dietary and supplemental viatmin D intakes and the plasma concentration of 25-hydroxyvitamin D (25-OHD). Median dietary intake was 88 IU for vitamin D, with 26% of the population taking a median supplement of 400 IU. Plasma 25-OHD was significantly lower in the elderly (15.5 ng/ml) compared to a younger control (29.1 ng/ml) population. Within the elderly population, the plasma 25-OHD demonstrated a seasonal influence (nadir in January, zenith in September) and was consistently higher for men compared to women. People taking vitamin D supplements had higher plasma 25-OHD concentrations regardless of seasonal influence. Plasma alkaline phosphatase, an index for bone loss, was inversely related to the plasma 25-OHD concentration. Inadequate dietary vitamin D intake and inadequate sunlight exposure appeared to be contributory to the observed low vitamin D status. It is suggested that American elderly consider using a combination of moderate vitamin D supplementation and increased sunlight exposure in order to improve their vitamin D nutriture.