But is the prevention of severe vitamin D deficiency such as rickets all we need to know?

FORBES: Vitamin D: Still More Questions Than Answers

But in northern Europe, diseases related to vitamin D deficiency, such as rickets, would have become common.

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Still, we can try to correlate vitamin D levels with obvious deficiency diseases such as rickets, but the environmental studies that look at other possible effects are problematic.

FORBES: Vitamin D: Still More Questions Than Answers

Stephen Nussey, professor of Endocrinology at St Georges Hospital in London, explained that rickets is a severe aspect of vitamin D deficiency.

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