Serum vitamin D level was measured in 122 patients with learning disabilities in long-term care wards. Such people are at risk of developing vitamin D deficiency. Low vitamin D is often attributed to lack of sunshine, poor dietary intake and the deleterious effect of anticonvulsant therapy. The results of this study confirmed that a low level of vitamin D (14.38 +/- 7.9 nmol/l) prevails, regardless of anticonvulsant usage. Sunshine exposure was virtually non-existent for most patients. Research has shown that when sunlight exposure is limited, osteomalacia in the British Asian community is determined by dietary factors. Our subjects had three types of diet: standard, soft and tube feeding. For both males and females, the tube feeding group had a significantly higher mean level of vitamin D than the other groups. Regular sunshine exposure is recommended for people requiring long-term infirmary care; alternatively, dietary supplement of vitamin D should be considered.