The Vitamin D, 25-Hydroxy (D2+D3 Fractionated) Blood Test includes:
- Total Vitamin D
- Vitamin D2
- Vitamin D3
What is the purpose of this test?
Order this Vitamin D, 25-Hydroxy (D2+D3 Fractionated) Blood Test to measure total Vitamin D and its two primary forms (D2 and D3) in the blood to screen for a deficiency or toxicity.
Vitamin D is essential for supporting overall health, especially healthy bones. Vitamin D allows the body to absorb vital minerals from food and maintain adequate calcium, phosphate, magnesium, and parathyroid hormone levels in the blood. Vitamin D also has a fundamental role in muscle movement by allowing the brain and body to communicate through our nervous system.
Additionally, research has shown that individuals with deficient vitamin D levels have increased risks of developing health problems such as:
- Heart disease
- Diabetes
- Certain cancers
What does the test measure?
Vitamin D can be consumed as a nutrient in the diet and produced as a hormone in the body through direct sun exposure. Therefore, the total Vitamin D in the body is made of 2 forms:
- Vitamin D2 (ergocalciferol) - is mainly produced in plants like yeast and mushrooms. In addition, D2 is available as a supplement and in fortified foods.
- Vitamin D3 (cholecalciferol) - is primarily found in animal products such as eggs, fish, and liver. D3 is also produced in the skin after exposure to direct sunlight. Like D2, D3 is offered as a dietary supplement and added to food products such as milk, juices, bread, and cereals.
Both vitamin D2 and D3 are occasionally used to treat people with vitamin D deficiencies or related disorders, such as rickets, hypoparathyroidism, hypophosphatemia, or osteomalacia.
Individuals should note that excessive vitamin D levels, referred to as vitamin D toxicity, can be as harmful as a deficiency. Vitamin D toxicity is caused by the overdosage of vitamin D supplements or overexposure to sunlight. Excessive amounts of vitamin D may cause damage to the kidneys and lead to elevated calcium levels in the bloodstream. This condition is known as hypercalcemia.
This Vitamin D, 25-Hydroxy (D2+D3 Fractionated) Blood Test may assist in the screening, diagnosing, and monitoring of a vitamin D deficiency or toxicity by measuring total vitamin D and each form. A traditional Vitamin D 25-Hydroxy Blood Test that measures total Vitamin D levels is also available.
When should I get a Vitamin D, 25-Hydroxy (D2+D3 Fractionated) Blood Test?
Individuals may order this test if they have experienced signs or symptoms of a vitamin D deficiency, such as:
- Bone or joint pain
- Muscle weakness or aches
- Soft, deformed, or broken bones
- Low bone density (osteoporosis or osteopenia)
Individuals may also order this test if they have an increased risk of developing a vitamin D deficiency, such as:
- Age over 65
- Obese or overweight
- History of weight loss surgery
- Osteoporosis
- Limited sun exposure, sunscreen use, or
- Dark skin pigmentation
- A condition that causes malabsorption of nutrients from foods (celiac disease and Crohn’s disease)
- Kidney and liver disease
- Use certain medications
