25-hydroxyvitamin D is an intermediate product of vitamin D metabolism in the body, and the adequacy of vitamin D levels in the body can be assessed by measuring the level of 25-hydroxyvitamin D. If the level of 25-hydroxyvitamin D is >50 nmol/L, the level of vitamin D is generally considered to be adequate. If the level of 25-hydroxyvitamin D is between 30 and 50 nmol/L, the level of vitamin D is considered to be insufficient. If the level of 25-hydroxyvitamin D