Vitamin B12 as a nutrient is essential for overall good health and is needed to treat or prevent certain ailments and conditions. Vitamin B12 can be obtained through your diet by eating meat, fish, poultry, and dairy products. It is also synthetically produced to be taken as a supplement, given via injections, or inhaled from vitamin B12 vape pen . Vitamin B12 Deficiency Sufficient levels of vitamin B12 are not always obtained from peoples diets due to trouble absorbing the vitamin. This can be age related, many elderly people are vitamin B12 deficient because their bodies struggle to absorb B12. Other conditions that can affect absorption rate are weight loss, surgery, heavy drinking, and lacking intrinsic factor in the intestine. Having a B12 deficiency can cause a myriad of health problems that can, in turn, be treated by supplementing vitamin B12 as a nutrient . Vitamin B12 Usages and Dosage Supplements - Vitamin B12 is taken orally for pernicious anemia, a condition in wh...