The Vitamin D Test measures levels of vitamin D, a key nutrient for bone strength and overall health. Your body produces vitamin D after exposure to sunlight or from consuming certain foods and supplements. Because it enables your body to absorb calcium, vitamin D is essential for healthy bones and also helps the immune system fight infections.
This test may be right for those who:
- Have a diet low in vitamin D rich foods such as egg yolks, fish such as herring, mackerel, and salmon, liver and organ meats, Vitamin D-fortified milk, orange juice, and cereals, and dairy products such as yogurt and cheese
- Have low exposure to sunlight
- Have a darker skin complexion
- Are overweight or obese
Abnormal vitamin D levels may have no symptoms, and some people can have abnormal vitamin D levels for years without knowing it. Some symptoms of low vitamin D levels include depression, fatigue, joint or muscle pain, and weakness. Low vitamin D levels can also affect organs and body functions including bone health, metabolism, heart health, and immune health.
The Vitamin D Test does not require fasting.
B12 is a vitamin that is necessary for normal red blood cell (RBC) formation, neurologic function, and DNA production. B12 must be supplied by the diet or supplementation because the body is not able to produce it.
People who are deficient in Vitamin B12 may not have any symptoms or may present with symptoms of anemia or nerve damage. General symptoms related to anemia and nerve damage include fatigue, weakness, difficulty concentrating, depression, numbness or tingling in the hands and feet, headaches, moodiness, and gastrointestinal symptoms. Some people may not have all or any of these symptoms but still have deficiency. Early detection is important to prevent irreversible damage over time, especially to the nervous system. Generally, people who are likely to have a B12 deficiency have:
- Problems absorbing the vitamin
- Poor or restricted nutritional intake
- Interference from a medication they are taking
- Increased energy requirements (eg, pregnancy)
This test may be appropriate for those who:
- Have a disorder that causes decreased absorption of certain vitamins or minerals
- Have a diet low in vitamin B12-rich foods (dairy, eggs, fish, poultry, or red meat)
- Are at risk for gastrointestinal absorption problems such as celiac disease, Crohn disease, partial bowel removal, pernicious anemia, atrophic gastritis
- Are pregnant or nursing
- Are 65 years and older
- Are a recent alcohol abuser
- Taking certain medications: long-term use of antacid drugs (proton pump inhibitor and H2 blockers), metformin (a diabetes medication) and chloramphenicol (an antibiotic)
The Vitamin B12 Test does not require fasting.
