Severe vitamin D deficiency in the institutionalized elderly

Abstract

Severe vitamin D deficiency has been found to be prevalent in institutionalized elderly persons in several countries. The aim of the present work was to assess the vitamin D status of institutionalized elderly and compare it to that of community-living independent elderly in southern Greece during summer. Serum 25-hydroxyvitamin D [25(OH)D] and plasma PTH were measured in 58 (aged 68-103 yr, median 83.5) elderly inmates of a nursing home (IE) in the town of Kalamata (latitude N 37 degrees ) and in 48 (aged 60-89 yr, median 72) community-dwelling elderly (CDE) in Athens (latitude N 38 degrees ). The CDE had mean serum 25(OH)D 67.6 nmol/l [95% confidence interval (CI) 57.4 to 79.5], not far from the value of 80 nmol/l which is generally considered to be the lower limit of vitamin D sufficiency. The IE had significantly lower mean 25(OH)D 19.0 nmol/l (17.1 to 21.1); values of 25(OH)D below 20 nmol/l characterize severe vitamin D deficiency and may cause osteomalacia. The group of CDE had significantly lower mean plasma PTH 1.5 pmol/l (1.0 to 1.8) compared to 4.5 (3.9 to 5.3) of IE. Ninety percent of CDE had normal plasma PTH whereas 60% of IE had secondary hyperparathyroidism (PTH values >4.0 pmol/l). In conclusion, the majority of institutionalized elderly in southern Greece had severe vitamin D deficiency and secondary hyperparathyroidism in contrast to the fairly good vitamin D status and lack of hyperparathyroidism in the community-living elderly during summer. These findings indicate the need for vitamin D and calcium supplementation of the institutionalized elderly throughout the year.