B12 Sublingual Liquid Remedy

Your body needs vitamin B-12, or cobalamin, to make DNA and red blood cells and for neurological function. Some people may have trouble absorbing vitamin B-12 in the digestive tract, so it is available in a form you can absorb under your tongue. If you have a B-12 deficiency, don't take sublingual B-12 drops without speaking with your doctor.

Digestion and Absorption

Vitamin B-12 is attached to proteins found in foods of animal origin or fortified cereals. It's released from the proteins in the stomach by hydrochloric acid and enzymes, then combines with intrinsic factor, a substance released by cells in the stomach lining, before moving into the small intestine. Vitamin B-12 must be bound to the intrinsic factor or it will not be absorbed into the bloodstream through the intestinal walls.

Recommended Intakes

The Food and Nutrition Board of the Institute of Medicine determines Dietary Reference Intakes, or "DRIs" for vitamin B-12. The DRI for children 1 to 3 years old is 0.9 mcg per day; children 4 to 8 years old need 1.2 mcg per day. Children 9 to 13 years old need 1.8 mcg per day and everyone 14 years of age and older needs 2.4 mcg per day. Pregnant women need 2.6 mcg per day and lactating women need 2.8 mcg per day.

B-12 Deficiency

Vitamin B12 deficiency is most commonly due to problems digesting or absorbing it. Older people may not make enough hydrochloric acid to break the vitamin free from the proteins. People with pernicious anemia don't make enough intrinsic factor to allow B-12 to pass through the intestinal wall. Vegans, who eat a diet of plant-derived foods only, may also be at risk for vitamin B-12 deficiency because it's not found in plants.

Sublingual B12

Vitamin B-12 deficiency is commonly treated with intramuscular injections. However, when B-12 is given in single doses of 500 mcg or more, the body can absorb only a very small amount. According to a study published in 2003 in "British Journal of Clinical Pharmacology," about 1 percent of the B-12 is absorbed, which is enough to reverse deficiency. B-12 supplements appear to be safe at high doses, but they may interact with certain medications, so don't take them before speaking with your doctor.