A new study suggests that high doses of vitamin D supplements could help reduce disease activity among multiple sclerosis ...

Taking too much vitamin D causes side effects like nausea, vomiting, weakness, and abdominal pain. The average adult should take no more than 4,000 international units of vitamin D daily.

Supplementing with vitamin D can lead to side effects. It can also lead to longer-term but rare problems. Such rare effects include: If you take high doses of vitamin D and experience symptoms of ...

Here's what to know about vitamin D3 benefits, sources, deficiencies, side effects and more. Vitamin D3 is a form of vitamin D. Vitamin D, or calciferol, is a fat-soluble vitamin that plays a key ...