25-Hydroxyvitamin D, known for its role in bone health and calcium absorption, also appears to affect immune function, neurodegenerative and cardiovascular issues, and other conditions. Vitamin D occurs in two forms—D3 is obtained from animal diet sources and through sun exposure, and D2 is obtained through vegetable diet sources. Both forms of the vitamin are used to fortify various foods and in supplements. We use the gold standard LC/MS QQQ method to measure Vitamin D2, D3 and total Vitamin D.
- Alzheimer’s Disease
- Bone Health
- Calcium Absorption
- Cardiovascular Disease
- Immune Function
- Multiple Sclerosis
- Neurocognitive Dysfunction
- Rheumatoid Arthritis
- Type 2 Diabetes
25-Hydroxyvitamin D is the major circulating form of vitamin D. It occurs in two forms: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol), and is the precursor of the active form (1,25-dihydroxyvitamin D).
Because of its long half-life, measurement of total 25-Hydroxyvitamin D (D2 plus D3) provides the best assessment of patient vitamin D status and includes vitamin D derived from diet, supplements, and exposure to UVB light, such as sunlight. Vitamin D is best known for its role in calcium and bone metabolism, but emerging research indicates that low levels of vitamin D may be associated with increased risk of some cancers, type 2 diabetes, multiple sclerosis, cardiovascular disease, rheumatoid arthritis, depression, Alzheimer’s disease, infections, preeclampsia, cesarean deliveries and neurocognitive dysfunction.
Vitamin D regulates the expression of a vast array of genes in tissues including immune cells, the vasculature, muscle and reproductive organs. Vitamin D insufficiency is common and deficiency can have adverse health effects at any stage of life.
Many testing methods do not differentiate between the two forms of vitamin D, and only total concentrations are reported. This LC/MS QQQ method is sensitive and specific for both vitamin D2 and D3, and each form is measured and reported independently.