Previously, the Endocrine Society defined vitamin D levels in terms of "deficiency" and "insufficiency" based on serum 25-hydroxyvitamin D (25[OH]D) levels. However, the new guidelines no longer ...

But here's a question: have you ever glanced at a bottle of vitamins and noticed a "best by" date? What does it mean, and does it matter if you take vitamins past that date? Let’s break it down.

That's why we created this helpful guide on vitamin B12 to help you learn more about vitamin B12 deficiency, supplements and injections. Vitamin B12 contains cobalt, hence its name, cobalamin.