Vitamin B12

Vitamin B12

By: Laura DeAndrade, ANP-BC

Vitamin B12 is an essential vitamin in everyone’s diet. Bariatric surgery enhances the need for this vitamin for a few reasons. Vitamin b12, also known as cyanocobalamin, is a water-soluble B vitamin. B vitamins help support adrenal function, help maintain a healthy nervous system, and are necessary for key metabolic processes. Vitamin B12 is important to DNA synthesis and maintaining healthy nerve cells. This crucial micronutrient affects the development and maintenance of red blood cells, nerve cells, and normal myelination (covering) of nerve cells. It also assists in the production of DNA and RNA, and the formation of neurotransmitters.

Vitamin B12 deficiency is one of the most common deficiencies observed after a gastric bypass and other bariatric procedures. Due to either a complete bypass of the stomach (gastric bypass) or the surgical creation of a much smaller stomach (sleeve), vitamin B12 is not absorbed the normal way that our body is used to. Under normal circumstances, the absorption of vitamin B12 begins in the mouth where small amounts are absorbed through mucous membranes. Vitamin b12 binds to intrinsic factor secreted by the stomach. It is this combination (B12 bound to intrinsic factor) that is absorbed further down in the intestines, in a portion called the ileum. During gastric bypass surgery, the portion of the stomach responsible for making intrinsic factor is bypassed. This portion of the stomach therefore never comes into contact with food so it is never stimulated to produce intrinsic factor. This lack of intrinsic factor decreases the amount the body is able to absorb. After a sleeve gastrectomy, the removed part of the stomach had been responsible for some of the production of intrinsic factor. Since there is not enough instrinsic factor binding to B12, deficiency can develop.

When a vitamin b12 deficiency occurs after bariatric surgery it is most often due to an inability of a person to absorb the vitamin, rather than poor dietary intake of the vitamin. Symptoms of a vitamin B12 deficiency can include all of the following:

  • numbess and tingling to the lower extremities
  • abnormal gait and problems walking
  • weakness, tiredness or lightheadedness
  • smooth tongue
  • depression, mood swings or memory loss

The only way to test for vitamin B12 deficiency would be through a blood test. These blood tests are done routinely after surgery to monitor for any deficiencies. Typically, patients who have had a gastric bypass or sleeve gastrectomy are asked to take 1000mcg of B12 in a sublingual form. Sublingual supplements are dissolved in the mouth under the tongue and are absorbed right into the blood. Another available option is intra-nasal supplementation available via a prescription from your healthcare provider. Lap band patients do not need to take additional daily supplements but should continue to take a Multivitamin that contains B12 as one of the ingredients.

Mary Anne

Mary Anne

START TYPING AND PRESS ENTER TO SEARCH