A recent paper published in the British Journal of Nutrition suggested possible reductions in mortality in association with the use of dietary supplements, giving specific findings for vitamins C and E and for fish oil(Reference Messerer, Håkansson, Wolk and Åkession1). In view of the randomized controlled trials of certain vitamin supplements in smokers that had to be curtailed because of adverse effects(2–Reference Virtamo, Pietinen, Huttenen, Korhonen, Malila, Virtanen, Albanes, Taylor and Albert4) these findings are, as the authors say, of considerable interest, especially since they are prospective, even though supplement use was self-selected in the 38 994 men studied.
Most multivitamin supplements available in the UK contain vitamin D and the use of vitamin D supplements has been reported to be associated with reductions in mortality rates and in all-cause mortality in two large prospective studies(Reference Autier and Gandini5, Reference Jia, Aucott and McNeill6). One wonders, therefore, why the above paper does not refer to vitamin D.
There is an obvious need to identify whether the current high prevalence of hypovitaminosis D worldwide is causally associated with many health risks, and for appropriate levels of supplementation to be identified(Reference Vieth, Bischoff-Ferrari and Boucher7). It would be of considerable interest and importance to know, therefore, whether vitamin D supplementation was examined by Messerer et al. (Reference Messerer, Håkansson, Wolk and Åkession1), whether mixed vitamin supplements in Sweden never contain vitamin D or whether there were no meaningful associations of vitamin D with the reported outcomes.
I declare no conflict of interest.
