Vitamin B12 deficiency After weight loss surgery
Research shows that most patients with obesity suffer from a deficiency of micronutrients such as Vitamin B12 before surgery. These deficiencies persist even after surgery. In this post, we will discuss Vitamin B12 deficiency, its symptoms, why it is prevalent after gastric surgery, and, what to do about it.
What is vitamin B12
Vitamin B 12 is a water-soluble B vitamin. It serves important functions in your body such as:
- Making DNA,
- Maintaining the nervous system (brain and spinal cord),
- Making red blood cells.
Your body cannot make vitamin B12. You have to get it from the food you eat such as, poultry, meat, fish and eggs, or, by taking supplements. As your body only retains the vitamin for 12-18 months, you should take these foods regularly
A key factor that might cause B12 deficiency is that most people don’t take enough of these foods, or, their bodies just cannot absorb enough of it. If you are on a vegan/vegetarian diet and don’t take supplements, you are also likely to be deficient.
There is also a strong co-relation between type 2 diabetes and vitamin B12 deficiency. Findings from the National Health and Nutrition Examination Survey, 1999-2006 showed that there is increased prevalence in vitamin B12 among adults who are diagnosed with type 2 diabetes.
How your body absorbs Vitamin B12
Vitamin B12 absorption follows this process.
During digestion in the stomach, hydrochloric acid separates Vitamin B12 from the R-protein. This is the protein that binds the vitamin to food.
The separated vitamin B12 attaches to intrinsic factor, a protein made by the parietal cells in the stomach.
The Intrinsic factor- vitamin B12 complex then binds to a vitamin B12 transporter called transcobalamin II. The transporter enters the degraded vitamin into circulation.
People with pernicious anemia cannot make intrinsic factor and their bodies therefore find it difficult to absorb vitamin B12 from food or supplements.
How gastric surgery causes Vitamin B12 malabsorption
Procedures such as Gastric Bypass result in changes in acid secretion. This leads to impaired absorption of vitamin B12.
Sleeve gastrectomy causes reduced acid production and lower levels of intrinsic factor and these changes directly affect iron and B12 absorption.
Deficiency is more commonly seen 2 years or more after surgery. Therefore, it is important to have frequent laboratory monitoring once you have had surgery. Further, women with low B12 levels may have a falsely abnormal Pap smear. This is because B12 affects the way epithelial cells look.
Symptoms of Vitamin B 12 deficiency:
- Diarrhea, gas, or constipation
- Light headedness
- Loss of appetite
- Pale skin
- Difficulty with concentration
- Shortness of breath and heart palpitations,
- Swollen, red tongue or bleeding gums.
- Mouth ulcers
- Impaired nerve function in cases of Long time Deficiency. This can result in symptoms such as:
- Loss of balance
- Numbness and tingling of hands and feet
- Problems with reflexes
If treatment does not begin within 6 months from the onset of symptoms, damage could be permanent.
To restore normal vitamin B 12 levels, you have to get weekly B12 injections and then monthly for several months. Alternatively, your doctor can prescribe, high-dose oral vitamin B12.