According to the Vitamin D Council, too much vitamin D can be harmful though it is considered one of the safest substances you could possibly ingest. Truth is, vitamin D toxicity is extremely rare. You are far more likely to be at risk for a vitamin D deficiency than an overdose. Nonetheless, a vitamin D overdose is possible.
So, what is vitamin D toxicity?
A vitamin D overdose can occur where blood serum concentrations of vitamin D’s storage form become excessively high, thereby causing adverse systemic effects. Our bodies have built in mechanisms for preventing a vitamin D overdose from sun exposure, either naturally or from tanning beds. Unfortunately, we can get an overdose of vitamin D through consumption of vitamin D supplements. The amount required for an overdose varies by individual and the exact proportions constituting an overdose have not been determined. For known cases, serum levels and dose involved intake equal to or greater than 40000 IU (1000 mcg) per day. In two different cases where two men consumed over 2,000,000 IU per day, toxicity and overdose where obvious but both individuals survived.
What are the symptoms of a vitamin D overdose?
Initially, someone who has consumed toxic levels of vitamin D may experience nausea, vomiting and abdominal cramps. This may be followed later by weakness and weight loss, tingling sensations in the mouth, confusion, heart rhythm abnormalities, constipation and/or diarrhea and confusion.
What to do if you think you’ve experienced a vitamin D overdose
If you think that you’ve had a vitamin D overdose, you should immediately stop supplementing with vitamin D, then have your 25(OH)D serum levels tested. If your test results show levels lower than 200-250 ng/mL you’re probably not toxic and may have experienced symptoms relating to an underlying magnesium deficiency, primary hyperparathyroidism, sarcoidosis or other potential causes.
Generally, a vitamin D overdose can be resolved without lasting damage by avoiding direct sunlight, restricting calcium intake, drinking at least 8 glasses of water each day and, of course, avoiding foods and supplements that contain vitamin D.
Vitamin D is not the only supplement you can overdose on. Take note of these others in the following video:
