[user104658]

Originally Posted by Kizzy

It's as much about lifestyle as diet, children do not spend enough time outside without sunscreen and other things preventing the sun getting to them.

Yes this is another problem, and comes from medical advice outdated by decades... from birth, people smother their kids in factor-50 (which is full of toxic crap in the first place, another issue, you should only use a natural factor 40 on kids!) sunscreen, completely blocking their ability to make Vitamin D through sun exposure. Even at the height of summer, they should be getting a little time outdoors before applying any at all, and with the lower light in the evening they can (and should) be getting exposure without any at all.

A few good sunny days with decent, unscreened outdoors time over the summer can set you up for the whole year. But if you're head to toe in cream before you even leave the house... then you might as well not leave the house at all.