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LETTERS: Stanley Zlotkin and Aubrey Blumsohn Vitamin D concentrations in Asian children living in England BMJ 1999; 318: 1417 [Full text]

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Vitamin D levels and Asian Children

Margaret Lawson   (17 June 1999)

Vitamin D levels and Asian Children 17 June 1999
Margaret Lawson, Senior Lecturer in Paediatric Nutrition Institute of Child Health, London Send response to journal: Re: Vitamin D levels and Asian Children	Vitamin D levels and Asian Children We would like to respond to the two letters 1,2 commenting on our recent short report 3 on the subject of vitamin D levels in Asian children. The diagnosis of rickets in a white infant associated with the use of a potent sunscreen is interesting. The author quotes a study linking the use of sunscreen with suppression of vitamin D 3 synthesis. However, a more recent study found no association between sunscreen use and Vitamin D metabolism4. In the current study no data was collected on the use of sunscreen, although perhaps this should be considered for future studies on Vitamin D. For both the Asian and the NDNS 5 study serum 25-hydroxyvitamin D was assayed with the INCSTAR kit which uses an equilibrium radio-immunoassay procedure, although there were some minor methodological differences between the two studies. In order to see whether these could in part explain the difference in values seen in the two studies a number of samples were analysed both in the Leicester laboratory, which analysed the samples for this study, and the Dunn laboratory in Cambridge, which analysed the national study. The two sets of values correlated very well and whilst the values from the Cambridge laboratory were slightly higher (mean difference +1.59nmol/l) the difference did not reach statistical significance. The suggestion that the low concentrations found in the Asian study may be a function of the analytical method therefore is not substantiated. Margaret Lawson, Senior Lecturer in Paediatric Nutrition Childhood Nutrition Research Centre Institute of Child Health, London WC1N 1EH 1 Zlotkin, S. Vitamin D concentrations in Asian children living in England. BMJ 1999; 318, 1417. 2. Blumsohn, A. Concentrations found may be function of analytical methodology used. BMJ 1999; 318, 1417. 3. Lawson, M.S., Thomas, M. Vitamin D concentrations in Asian children Aged 2 years living in England: population survey. BMJ 1999: 318, 28. 4. Farrerons et al.. Clinically prescribed sunscreen does not decrease serum vitamin D concentration sufficiently either to induce changes in parathyroid function or in metabolic markers Brit. J. Dermatol 1998; 139, 422. 5. Gregory et al. 1995. National Diet and Nutritional Survey: Children aged 1.5-4.5 years. London. HMSO.