It can be measured with a blood test: > The most accurate way to measure how much vitamin D is in your body is the 25-hydroxy vitamin D blood test. https://ww

It can be measured with a blood test: > The most accurate way to measure how much vitamin D is in your body is the 25-hydroxy vitamin D blood test. https://www.webmd.com/diet/guide/vitamin-d-deficiency https://www.webmd.com/diet/guide/vitamin-d-deficiency