How can I tell if my Vitamin D levels are too high?

Everyone taking high doses of Vitamin D should be under the care and supervision of a physician. A blood test can be administered by your physician to measure your 25(OH) D levels. If your 25(OH) D levels are above 150 ng/ ml then this is considered to be potentially toxic. A blood test to measure calcium can also measure 25(OH) D levels. If your calcium levels are high and 25(OH) D is high, then you may be getting too much Vitamin D.