(HealthDay News) -- Vitamin B-12 is an essential vitamin that supports the nervous system, creation of red blood cells and production of DNA. It's primarily found in seafood, meat and dairy products.
If you have low levels of vitamin B-12, it could be because you're not eating enough of these products, or you're having trouble absorbing the vitamin from foods.
The American Academy of Family Physicians says possible reasons for poor absorption of vitamin B-12 include: