[Vitamin D deficiency and osteomalacia in old people (author's transl)].

The frequency and causes of vitamin D deficiency in old age were investigated in 53 hospital patients, 88 persons from old people's homes, 21 tenants of a hostel, and 29 members of a seniors meeting group, aged between 65 and 93 years. In all persons 25-hydroxyvitamin D, calcium, phosphate, alkaline phosphatase, leucine arylamidase and creatinine were determined. In 27 cases immunoreactive parathormone was measured. In hospital patients there was evidence of vitamin D deficiency significantly more frequently as compared with the other groups. The 25-hydroxyvitamin D concentration was on average lower in the cases from old people's homes and hostels than in the members of the seniors group. The results in the groups investigated showed a relation to the average exposure to the sun. The results in 10 further patients in this age group with florid osteomalacia indicate a multifactorial aetiology of vitamin D deficiency disease due to reduced exposure to sun, inadequate nutrition and reduced absorption of vitamin D.