There are two forms of vitamin D in the blood: 25-hydroxy vitamin D, or calcidiol, and 1,25-dihydroxy vitamin D, or calcitriol. Tests will measure the amount of 25-hydroxy vitamin D in the blood. This ...

Should you get a blood test to see if you're deficient in vitamin D? It sounds like such a good idea, seeing as how most people don't get enough sunshine to make vitamin D themselves. And the tests ...

Some vitamin D tests may give misleading results despite progress made in recent years to improve the quality of these assays, according to the US Centers for Disease Control and Prevention (CDC).

Vitamin D tests certified by the U.S. Centers for Disease Control and Prevention (CDC) Clinical Standardization Programs (CSP) are well calibrated overall, according to a new study presented Sunday at ...

How to use an at-home vitamin deficiency test For any further questions, all reputable at-home tests will have instructions and a customer care line. Most vitamin deficiency tests require a blood ...

It's Wellness Wednesday, and this week’s focus is on vitamin D and its role in overall health. Many people assume they’re getting enough during the summer months, but that’s not always the case. We ...

Lauren Silva, a freelance writer in New York City, believes in feeling good in your body and making that experience accessible to everyone across generations. The proof is in her ever-piling browser ...

Jane McClenaghan on how to make sure you’re getting just enough of this essential nutrient - without overdoing it ...

Two new lab tests to measure blood levels of vitamin D are inaccurate more than 40% of the time, according to a new study. Researchers say newer tests tend to overestimate the number of people who are ...

More than 40% of Americans are living with a silent deficiency, but experts warn that while the "Sunshine Vitamin" is ...

BOSTON (Reuters) - Quest Diagnostics Inc said on Thursday that it had provided possibly erroneous results to thousands of people who had their vitamin D levels tested over the past two years. Quest, ...

If symptoms develop soon after taking a supplement, intolerance to supplement ingredients is also a possibility. Since ...