Risk factors

A number of factors can affect your body's vitamin stores. In general, your risk of vitamin deficiency is increased if:

• Your diet contains little to no natural vitamin food sources, such as meat, dairy, fruits and vegetables. Vegetarians who don't eat dairy products and vegans, who don't eat any foods from animals, may fall into this category.

  Consistently overcooking your food also can cause vitamin deficiency.

• You're pregnant, and you aren't taking a multivitamin. Folic acid supplements are especially important during pregnancy.
• You have intestinal problems or other medical conditions that interfere with absorption of vitamins. Abnormal bacterial growth in your stomach or surgery to your intestines or stomach can interfere with the absorption of vitamin B-12.
• You abuse alcohol. Alcohol interferes with the absorption of folate and vitamin C, as well as other vitamins.
• You take certain prescription medications that can block absorption of vitamins. Anti-seizure drugs can block the absorption of folate. Antacids and some drugs used to treat type 2 diabetes may interfere with B-12 absorption.