Included in the home vitamin D test kit: 2 lancets 1 Vitamin D blood spot card 1 envelope for returning the card 1 gauze pad, 1 band aid, and 1 alcohol swab Vitamin D literature The most accurate determination of vitamin D status is the measurement of 25-hydroxyvitamin D, or 25(OH)D, in the blood. A Scientists’ Call to Action has been issued by 48 international vitamin D researchers to alert the public to the importance of having vitamin D serum levels between 40 and 60 nanograms/milliliter (ng/ml) (100-150 nanomoles/liter, nmol/L) to prevent disease. Almost 90% of U.S. adults have vitamin D levels below that range. After receiving your result, use the D*Calculator to estimate an appropriate amount of vitamin D supplementation. Testing, and re-testing 3-6 months after making your adjustments, is the only way to find out if you are in the target range for vitamin D. The blood spot assay is performed using liquid chromatography/ tandem mass spectrometry (LC-MS/MS), the same method used by the CDC Nutrition Laboratory to obtain accurate 25(OH) D values. Method accuracy is ensured by standardization with the NIST vitamin D standard reference materials. Circulating 25(OH)D3 levels reflect endogenous production as well as vitamin supplementation, whereas 25(OH)D2 levels reflect the results of Vitamin D2 supplementation. Vitamin D2 is believed to be less bioactive than vitamin D3. Vitamin D deficiency is linked with many chronic diseases, including autoimmune diseases, diabetes, cardiovascular disease, and cancer. Optimal levels of 25(OH)D3 are 32—100 ng/mL. Vitamin D3 (cholecalciferol) is a prohormone produced endogenously from the action of ultraviolet light on its precursor, 7-dehydrocholesterol, in the skin, and is also commonly found in over-the-counter vitamin D supplements. Vitamin D2 (ergocalciferol) does not occur naturally, but is manufactured commercially by exposing ergosterol to ultraviolet light, and is the predominant form obtained by prescription in the US. Both are hydroxylated in the liver to form their 25-hydroxy metabolites (25(OH)D2 and 25(OH)D3), the major circulating form of vitamin D in the blood and the commonly accepted measure of vitamin D status. Vitamin D supplements taken in the same amount can produce hugely different blood levels in different individuals due to a number of dietary, lifestyle, and individual factors. The presence or absence of vitamin D cofactors (such as magnesium or vitamin K), malabsorption issues (such as a food intolerance), the time of day, whether you take your supplement with food, and whether you smoke or take prescription or over-the-counter medications will all influence blood levels in response to supplementation. It is important to remember that it is the blood level that has been related to specific health outcomes, not simply the intake amount.Learn more about the importance of measuring your vitamin D level and research involving vitamin D at www.grassrootshealth.net.
