Final Answer:
The diagnostic test for Vitamin D deficiency is a blood test that measures the levels of 25-hydroxyvitamin D (25(OH)D) in the bloodstream.
Step-by-step explanation:
The most common diagnostic test for Vitamin D deficiency involves measuring the concentration of 25-hydroxyvitamin D (25(OH)D) in the blood. This form of Vitamin D is the major circulating metabolite and is considered the best indicator of a person's Vitamin D status. The blood test is usually performed using a sample obtained through a simple blood draw.
The reference range for normal Vitamin D levels can vary, but generally, levels below 30 nanograms per milliliter (ng/mL) are indicative of Vitamin D deficiency. Results in the range of 30 to 50 ng/mL may be considered insufficient, and levels above 50 ng/mL are often considered adequate.
The diagnostic test for Vitamin D deficiency is a blood test that measures the levels of 25-hydroxyvitamin D (25(OH)D) in the bloodstream.