Medically reviewed by Erika Prouty, PharmD Key Takeaways Vitamin B12 is generally safe, but rare reactions like allergies or ...

What happens if your body has too much vitamin B12? Read on to find out the dangerous side effects of having excessive levels ...

If you're not getting enough vitamin B12 from food, a supplement can help fill the gap. Here's what experts recommend for taking it.

Self-medicating with vitamin B12 without a doctor’s guidance is not a good idea. Even though B12 is water-soluble (meaning excess amounts are usually flushed out in urine), taking more than your body ...

Supplements may negatively affect sleep quality due to their ingredients, mode of action, or the timing of doses. Some vitamins, such as melatonin, promote relaxation and induce sleep. Others can act ...

DEAR DR. ROACH: I am 73, and I was worried about dementia. Turns out, I am “normal.” However, the neurologist told me to take 2,000 mcg of B12 daily. My multivitamin has 100 mcg, which is 4,167% of ...

DEAR DOCTOR: I'm almost 90 years old and always tired. I took two capsules of 2,000 mcg vitamin B12 the other night, and felt stronger and not as tired. Is it safe? DEAR READER: My first thought is ...

Our body needs a variety of different vitamins and minerals to thrive, including eight different B vitamins. And out of all of them, vitamin B12 might be the most popular. But what exactly is B12, and ...

"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." It’s normal to wonder if you’re meeting your nutritional needs if you’re feeling off in your day-to-day.