A vitamin D test is a blood test that measures the level of vitamin D (calciferol) in your blood. It can indicate whether the vitamin D levels in your body are low or high. Low vitamin D levels can ...

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 the ...

Swiss-based Roche announced this month that it has received U.S. regulatory clearance for a less-complex vitamin D test in the United States, which the company said opens the door to more efficient ...