How do i test my vitamin d levels?

Blood: Hi. 25-hydroxyvitamin D level in serum is used to test vitamin D adequacy. If low, it's very easy to treat.

Vitamin D levels: A blood test is required to determine Vit D level, called a 25 (OH)D blood test. When you get your results they'll be expressed in "units" of ng/ml. To convert a result in ng/ml to one measured in nmol/I, just multiple x 2.5. If your level is between 0-10 ng/ml, you're deficient in Vit D and you should see your physician to implement a replacement program.