Clinical and Histological Spectrum of Osteomalacia Among Asians in South London

In a prospective study of 175 adult Asian patients attendinga medical out-patient clinic we found a spectrum of metabolicbone disease. Twenty-four patients (13.5 per cent) had definiteosteomalacia, of whom 11 (6 per cent) had severe clinical osteomalaciaon the basis of associated symptoms and radiological signs.Fifteen (8.5 per cent) had borderline osteomalacia, while theremaining 136 (78 per cent) had normal bone biopsy, or werepresumed to be normal. This histological spectrum was paralleled by the increasingprevalence of musculoskeletal symptoms (thi gh pain, changein gait and difficulty rising from seated position) attributableto osteomalacia. Multivariate analysis showed that the majordeterminant of osteomalacia in Asians in South London was vegetariandiet. Increasing severity of bone disease was associated withincreasingly strict vegetarian practice, which accounted forthe excess risk of females, Hindus, and Asians originating fromEast Africa. Covering skin when outdoors also contributed tothe female excess risk, and suggested a role for reduced solarexposure. Clinically significant osteomalacia is underdiagnosed in theAsian population, but evidence of dietary adaptation suggeststhis problem may diminish with time.