Letters

Sunlight and health

BMJ 1999; 319 doi: http://dx.doi.org/10.1136/bmj.319.7216.1066 (Published 16 October 1999) Cite this as: BMJ 1999;319:1066

Use of sunscreens does not risk vitamin D deficiency

  1. Robin Marks, professor of dermatology
  1. St Vincents Hospital, Melbourne, Fitzroy Victoria 3065, Australia [email protected]
  2. Cancer Screening Evaluation Unit, Institute of Cancer Research, Sutton, Surrey SM2 5NG
  3. Department of Photobioology, St Thomas's Hospital, London SE1 7EH
  4. Imperial Cancer Research Fund General Practice Research Group, Institute of Health Sciences, University of Oxford, Oxford OX3 7LF
  5. Department of Medicine, Manchester Royal Infirmary, Manchester M13 9WL
  6. Department of Social Medicine, University of Bristol, Bristol BS8 2PR

    EDITOR—Ness et al misinterpret our work in Australia by stating that we showed that use of sunscreens reduced vitamin D concentrations.1 In fact, we showed that the use of sunscreens did not prevent the normal summer rise in 25-hydroxy vitamin D concentration (the vitamin D fraction that is used to assess vitamin D deficiency).2 Subjects using sunscreens compared with controls using a placebo cream had an equal rise over the summer.

    As an extension of the study we also measured concentrations of 1, 25-hydroxy vitamin D. This fraction of vitamin D is believed to be regulated by 25-hydroxy vitamin D concentrations via a negative feedback mechanism. We found a rise in 1, 25-hydroxy vitamin D concentrations over the summer in people using sunscreen, but the rise was smaller than that among those using placebo. In a small group there was a lower, but not significantly different, concentration of 1, 25-hydroxy vitamin D at the end of summer. However, this occurred in the presence of a substantial rise in 25-hydroxy vitamin D concentrations (the vitamin D fraction that controls 1, 25-hydroxy vitamin D) in all subjects. We also made it clear in our paper that the 1, 25-hydroxy vitamin D concentrations of all the participants in the placebo and sunscreen groups remained within the normal range all the way through the study.

    It is mischievous and specious to imply that our work was suggesting that use of sunscreen might lead to vitamin D deficiency. We made the opposite point very strongly in the paper and clearly explained why, in the presence of raised 25-hydroxy vitamin D concentrations, the slightly smaller changes in 1, 25-hydroxy vitamin D could not be interpreted as a risk for vitamin D deficiency.

    References

    1. 1.
    2. 2.

    Article did not help informed debate

    1. Jane Melia, epidemiologist ([email protected])
    1. St Vincents Hospital, Melbourne, Fitzroy Victoria 3065, Australia [email protected]
    2. Cancer Screening Evaluation Unit, Institute of Cancer Research, Sutton, Surrey SM2 5NG
    3. Department of Photobioology, St Thomas's Hospital, London SE1 7EH
    4. Imperial Cancer Research Fund General Practice Research Group, Institute of Health Sciences, University of Oxford, Oxford OX3 7LF
    5. Department of Medicine, Manchester Royal Infirmary, Manchester M13 9WL
    6. Department of Social Medicine, University of Bristol, Bristol BS8 2PR

      EDITOR—Debating the content of health education messages, the scientific evidence on which …

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