Dr Boucher raises the question of the use of vitamin D supplements in the prospective population-based study of mortality performed among 38 994 Swedish men(Reference Messerer, Håkansson, Wolk and Åkession1). The main finding of this study was increased cancer mortality among smokers who used any supplement (unspecified) as compared with non-users. Among individuals with inadequate diet we observed that supplement users had decreased cardiovascular mortality as compared with non-users. The question brought up by Dr Boucher was whether vitamin D supplementation was examined specifically and whether mixed vitamin supplements in Sweden contain vitamin D. Moreover, were there any meaningful associations of vitamin D with the reported outcomes?
The use of vitamin D supplements was not specifically addressed at baseline in 1997 in our cohort. At that time, there were fewer mixed preparations on the market containing vitamin D than today. Nowadays most multivitamins in Sweden, as seems to be the case in the UK, contain vitamin D. The amount of vitamin D in these combined preparations, multivitamins or in combination with Ca, is generally 5–10 μg per pill (recommended dose is one pill per d). In contrast to many countries, preparations with a low dose of only vitamin D specifically are not available at pharmacies. Our results mainly concerned the use of any unspecified dietary supplement so we cannot draw any conclusion regarding the association of vitamin D supplementation with mortality.
We declare no conflict of interest.
