Gastrointestinal symptoms
The main vitamin D side effects of excessive levels are linked to excessive calcium in the blood. Taking vitamin D can raise calcium levels in the blood, and getting an intake of too much calcium can cause some significant side effects.
Taking extreme doses of vitamin D, you might experience loss of appetite, stomach pain, constipation, or diarrhea due to raised calcium levels. Some of the main signs of hypercalcemia include:
-Poor appetite
-Nausea
-Vomiting
-Constipation
-Diarrhea
But remember, not all individuals with hypercalcemia experience the same vitamin D side effects. One woman experienced weight loss and nausea after taking a supplement discovered to contain 78 times more vitamin D than declared on the label.
Notably, these vitamin D side effects occurred in response to overly high doses of vitamin D3, which led to her calcium levels being more significant than 12 mg/dL.
