Prevalence of hypovitaminosis D in Indo-Asian patients attending a rheumatology clinic

Abstract

This study was performed to determine the prevalence of hypovitaminosis D (HD) and hypovitaminosis D associated with secondary hyperparathyroidism (HD-SHPT) among Indo-Asians attending rheumatology clinics in Wolverhampton. A cross-sectional survey of 98 clinic attenders and 36 normal controls subjects was undertaken. The groups were matched for age, gender, and body mass index. There was a high prevalence of vegetarianism, and milk consumption was low in both groups. Clinical scores for musculoskeletal pain, gait, and muscle strength were all significantly worse in clinic attenders (p < 0.001). Comparing clinic attenders with controls, 25-OH-vitamin D levels were 6.6 +/- 3.9 vs. 8.2 +/- 4.8 microg/L (p < 0.01) and the prevalence of HD (<8 microg/L) was 78% vs. 58% (p < 0.05), but neither parathyroid hormone levels (53 +/- 60 vs. 50 +/- 18 ng/L, n.s.) nor HD-SHPT prevalence (22% vs. 33%, n.s.) were significantly different. Routine biochemical tests were not discriminant, but none of the controls and 10 of 98 (10%) clinic attenders had elevated alkaline phosphatase levels: 6 with HD and 3 with HD-SHPT. Vitamin D deficiency has an extremely high prevalence among Indo-Asians in the U.K., particularly in those attending rheumatology clinics. Detection of HD and HD-SHPT is only possible using measurements of 25-OH-vitamin D and PTH.