People can get vitamin D from exposure to sunlight or, to a lesser extent, from food. If one is unable to get enough vitamin D from these sources, they can develop a deficiency. If doctors observe the signs of a Vitamin D deficiency in a patient, they are likely to recommend a Vitamin D blood test.
Vitamin D is an important nutrient for maintaining healthy bones and teeth. There are two forms of vitamin D that are vital for the human body: vitamin D2 and vitamin D3. Vitamin D2 mainly comes from fortified food items like breakfast cereals, milk, and other dairy items. On the other hand, Vitamin D3 is made by the body of a person when they are exposed to sunlight
Typically, both vitamin D2 and D3 have to undergo chemical changes before being able to be used by the body. Such changes take place in the kidneys and the liver, where Vitamin D is converted into measurable substances known as 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D:
25-hydroxyvitamin D
Vitamin D is converted into 25-hydroxyvitamin D in the liver. 25-hydroxyvitamin D is also known as 25(OH)D. In most cases, vitamin D levels are tested by analyzing blood levels of 25(OH)D. This test is known to be a highly accurate way of analyzing how much vitamin D is in the body as 25(OH) is the major form of vitamin D that circulates in the bloodstream.
1,25-dihydroxyvitamin D
25 (OH) D is converted into a hormone called active vitamin D or 1,25-dihydroxy vitamin D in the kidneys. At times, labs check the blood level of 1,25-dihydroxy vitamin D, which is also called 1,25(OH)2D. This test is used as a second-order test in the assessment of vitamin D status, especially in patients with renal disease.
Who should get a vitamin D test?
Doctors recommend Vitamin D tests to determine if the patient has a deficiency, insufficiency, or toxic level of vitamin D. The test can also be done to monitor the treatment for a previously diagnosed deficiency. Ideally, doctors recommend people experiencing the following signs and symptoms of a vitamin D deficiency to go for the test:
- Bone pain
- Seizures
- Bone deformity
- Dental abnormalities
- Weakening of the bones
- Abnormal bone development
- Muscle weakness or cramps
Vitamin D blood test cost and other details can be found online.
What’s the Normal Range of Vitamin D?
- Deficient – <20 ng/mL / (<50 nmol/L)
- Insufficient – 20 – <30 ng/mL / (50 – <75 nmol/L)
- Sufficient – 30 –100 ng/mL / (75 – 250 nmol/L)
- Potential Toxicity – > 100 ng/mL / (> 250 nmol/L)
Going for the Blood Test
Patients can either visit a clinical laboratory to get a Vitamin D test done or opt for blood test home collection. The latter has become a popular choice among people today owing to the high level of convenience it provides. Home collection eliminates the need for patients to travel to a laboratory, wait in line, or take time off work. It is particularly beneficial for individuals with mobility issues, and busy schedules, as well as the ones who live in remote areas. With home blood tests, one also gets to choose the most convenient time for sample collection. There are many service providers today that offer the option for both lab and home sample collection. The reports of the test results are also made available to the patients digitally, so that they do not have to visit the lab again to collect their reports.
