The NHS in the UK recommends everyone takes vitamin D supplements in autumn and winter, but says "Do not take more than 100 micrograms (4,000 IU) of vitamin D a day as it could be harmful." and talks specifically about the risk of high calcium levels. https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-...

This presumably has a lot to do with latitude though - there aren't many months in the UK where I regularly walk around with arms and legs uncovered.