Vitamin D tests involve taking a blood sample to measure the vitamin D levels in your bloodstream. There are two forms of vitamin D in the blood: 25-hydroxy vitamin D, or calcidiol, and 1,25-dihydroxy ...

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 ...

Nearly a quarter of Americans are estimated to have a vitamin D deficiency. Why is that? A 2022 study of National Health and Nutrition Examination Surveys (NHANES) data estimated that about 22% of ...

Scientists are still untangling why the nutrient gap persists—and what it reveals about how women’s health is studied and treated.