‘We already know a lot about vitamin D deficiency in the elderly,’ says Feskens. ‘Women over 50 and men over 70 often have a vitamin D deficiency. And dark-skinned people too. It is interesting that someone is taking a good look at children now too.’
Do the results of the study surprise you?
‘The problem among children is really new to me, but actually it is very logical that it should be studied. After all, vitamin D is crucial to good bone development. Roughly until the age of 30, bone is being built up, and after that bone mass starts to diminish. Good bone building in early life reduces the chances of osteoporosis in old age. It is recommended that children be given vitamin A and D supplements. This study shows that this is not being done enough.’
10,000 children in Rotterdam were involved in this study. How did the researchers manage that?
‘This is part of the Generation R Study in which the growth and development of 10,000 children from Rotterdam is being monitored from birth, with cooperation from their parents. Wageningen UR is collaborating on this study too. We will soon be publishing on the subject of diet and sleeping habits in young children, together with Trudy Voortman, the Rotterdam PhD researcher who did this vitamin D study.’