Supplements Guide: Side Effects & Best Multivitamins

Vitamins and supplements like melatonin and fish oil offer health benefits but can cause side effects if misused. Learn about the impact of saw palmetto on blood pressure and find the best multivitamins for young women and adults over 50.

How Often Can You Inject B12?

Published Jul,08 2011 | By Chris Chandler

Your doctor may prescribe vitamin B12 injections if you have low levels of B12 in your blood, a condition known as vitamin B12 deficiency. B12 deficiency can result if you don't eat enough of certain foods, particularly meat, poultry and seafood, or if you have an inability to absorb vitamin B12 from food.