A pharmacist’s warning about vitamin D usually relates to taking too much, taking it unnecessarily, or ignoring interactions and health conditions. Vitamin D is important for bone health, muscles, and immune function, but more is not always better.
Things to know if you take vitamin D
- Avoid very high doses unless advised by a healthcare professional
Excess vitamin D can cause high calcium levels in the blood (hypercalcemia), which may lead to nausea, constipation, weakness, excessive thirst, frequent urination, or confusion. - Check the dose on your supplement
Many people take vitamin D safely at recommended amounts, but some high-dose products are intended only for specific medical situations and monitoring. - Be careful if you have certain health conditions
Speak with a healthcare professional before taking vitamin D supplements if you have conditions such as:- Kidney disease
- A history of kidney stones
- Certain disorders affecting calcium levels
- Sarcoidosis or other conditions that can affect vitamin D metabolism
- Consider medications and supplements you already use
Vitamin D can interact with some medicines, including certain diuretics and other treatments that affect calcium balance. - Testing may be useful for some people
A blood test can check vitamin D status when deficiency is suspected or when higher-dose treatment is being considered.
When vitamin D may be especially important
Older adults, people with limited sun exposure, people with darker skin living in low-sunlight areas, and those with conditions affecting absorption may be more likely to have low vitamin D levels.
If you take vitamin D regularly, the key questions are: What dose are you taking, why are you taking it, and has your level been checked when appropriate? A healthcare professional can help determine whether your supplement and dose fit your needs.
