Endocrine Abstracts

Background: Vitamin-D deficiency and type 2 diabetes (T2D) are common in South Asians (SA). The diagnosis of a vitamin-D deficiency in the setting of a chronic disease depends on a high index of suspicion and adequate investigation. This involves bone profile, occasionally in conjunction with serum 25-hydroxyvitamin-D. The ability of routine investigations to identify vitamin-D deficient patients have not been widely studied.

Aims: To assess the ability of routine biochemistry to detect vitamin-D deficiency.

Methods: A cross-sectional study. One seventy patients with and 40 without T2D were randomly selected. All participants were SA, >40 years old, had normal creatinine and none were taking any calcium or vitamin-D supplements. Data collected: demographics, PTH, calcium, phosphate, alkaline phosphatise (ALP), urea&creatinine, and serum 25-hydroxycholecalciferol-D. Vitamin-D deficiency was defined by serum 25-hydroxycholecalciferol levels <12.5 nmol/l.

Results: Twenty seven (14%) patients in the entire cohort were vitamin D deficient. Only 6 (22%) of the vitamin-D deficient patients had abnormal bone profiles. 5 (18.5%) had a low phosphate, 2 (7.4%) a high ALP and none a low calcium. 1 (3.7%) patient had more than one abnormality. However, these patients did have significantly lower Vitamin D levels (10 vs 30 nmol/l; P=0.002) and an abnormal bone profile may therefore be a marker of more severe disease. The remaining 21 (78%) would have been missed by routine biochemistry alone. PTH was elevated in only 63% of vitamin-D deficient patients and is therefore inadequate as a screening tool.

Conclusion: Vitamin-D deficiency is common in UK SA with and without T2D. The majority of vitamin-D deficient patients had a normal bone profile and more than a third had normal PTH. Routine bone profiles and PTH levels are insensitive and should not be used for screening. However, they may provide value in assessing disease severity.