The NIH notes that symptoms of vitamin D toxicity are most likely to appear when a person’s daily intake is at least 10,000 IU (250 mcg). However, experts have cautioned that much smaller ...
Historically, 400 IU (10 ug) of vitamin D was recommended for better health because it closely approximated the amount of vitamin D in a teaspoonful of cod liver oil. However, 800 to 1,000 IU is ...