B12 Deficiency Affects the Body

How Vitamin B12 Deficiency Affects the Body: Signs, Symptoms, and Treatments

December 14, 2022

How Vitamin B12 Deficiency Affects the Body: Bariatric surgery creates a major overhaul in diet and lifestyle choices. Not only are your eating, drinking and exercise habits drastically changed, but you also must ensure the body is getting adequate amounts of vitamins and minerals to function properly. There are several important vitamins that are of concern after going under the knife, but one in particular is vitamin B12.

B12 is a water-soluble vitamin that is mostly eliminated through the urine after the body takes what it needs to function but is also stored in the liver for long-term use. It is found in a variety of foods and is often added to processed foods to make them more nutritious. B12 contains a mineral, cobalt, and comes in a variety of forms, with two being the most widely known and used in supplements: cyanocobalamin and methylcobalamin. Methylated B12 (methylcobalamin) is the easiest to absorb and is best for those individuals who have the gene mutation, MTHFR. Vitamin B12 plays a role in many bodily functions including:

  • Development and function of the central nervous system.
  • Red blood cell development/function.
  • DNA formation.
  • Overall energy levels.
  • Prevention of specific blood disorders such as pernicious anemia.

Vitamin B12 needs a glycoprotein called intrinsic factor, which is produced by the parietal cells in the stomach, to be absorbed properly. It binds to B12 and helps the body absorb it properly. Since the stomach size is drastically reduced through bariatric surgery, there is naturally less intrinsic factor available. This is a problem when it comes to B12 containing foods; absorption is very low. Because of this, individuals that have gone through weight loss surgery need to supplement with B12. It is also recommended that B12 be administered through dissolvable tablet, sublingual liquid, intramuscular shot, or nasal spray. This way, absorption rate is likely higher since it bypasses the stomach for digestion.

Not only does bariatric surgery itself hinder B12 absorption, but certain medications can also have an effect. If a patient takes any of the following medications, it is even more important for daily B12 supplementation. Medications that can decrease B12 absorption include metformin, proton-pump inhibitors (omeprazole, zantac, etc.), nitrous oxide, seizure medications, colchicine (anti-inflammatory for gout), and neomycin (antibiotic).

Low levels of B12 can also be a result from excessive vomiting, food intolerances, or low intake of protein and vitamin B12-containing foods. If an individual is of older age or has an autoimmune condition like Crohn’s or Celiac, they are at a higher risk of becoming deficient in B12 due to absorption issues. Those who follow a vegan or vegetarian diet are also at risk due to the absence of animal food sources.

Performing routine lab work post-WLS is crucial to ensure prevention of complications from vitamin deficiencies, especially B12. Many clinics will have patients perform lab work within the first 3 months after surgery and at regular intervals afterwards. ASMBS recommends B12 screening every three months for the first-year post-op. After one year, labs can be reduced to yearly or as recommended by a physician.

The normal accepted range for B12 levels is 200-1500 ng/l. If you are low or deficient, you may likely experience some or most of the following signs and/or symptoms.

Early signs and symptoms of deficiencies are:

  • Pernicious anemia/megaloblastic anemia
  • Pale skin with slightly yellowing skin and/or eyes
  • Magenta or “beefy red” tongue (glossitis)
  • Fatigue
  • Anorexia
  • Diarrhea
  • Numbness and tickling/prickly feeling in extremities
  • Poor muscle coordination (ataxia)
  • Changes in reflexes.
  • Light-headedness or vertigo
  • Shortness of breath.
  • Ringing in ears (tinnitus)
  • Heart palpitations or rapid pulse

Advanced signs and symptoms:

  • Chest pain (angina)
  • Symptoms of congestive heart failure
  • Altered mental status: mild irritability/cognitive forgetfulness to severe dementia or psychosis

If you are experiencing any of the above signs and/or symptoms, it is recommended to first contact your bariatric clinic, primary care physician or visit your local ER. B12 deficiency is relatively low in patients who are 1-year post-op. For RYNGB patients, less than 20% are B12 deficient at 2-5 years post-op. Between 4 and 20% of Sleeve Gastrectomy patients are B12 deficient during the same time frame. B12 deficiencies may take a long time to present through physical signs and/or symptoms since the body can store it for some time. Maintenance dosage recommendations and correctional dosage recommendations for B12 vary:

  • ASMBS clinical guidelines recommend that all weight loss surgery patients supplement with B12. The dose is based on route of administration (nasal, oral, etc.). Orally by sublingual tablet or liquid: 350-500 mcg per day. Nasal spray: as directed by the manufacturer. Intramuscular or subcutaneous injection: 1000 mcg once monthly. For dissolvable tablets, it is best to allow 20-30 seconds to dissolve fully.
  • If a patient is deficient, it is recommended to take 1000 mcg per day to achieve normal levels or until symptoms subside, then resume normal dosage recommendations for maintenance.
  • Most bariatric brand multivitamins contain the required amount of B12 post-WLS, but always be sure to check the nutrition label.

Although supplementation is the main source of B12 after WLS surgery, it is also important to include a variety of B12-containing foods such as:

  • Organ meats
  • Clams
  • Sardines
  • Beef
  • Tuna
  • Fortified nutritional yeast
  • Fortified breakfast cereals
  • Trout
  • Salmon
  • Milk and dairy products
  • Eggs

Although rare, B12 deficiencies can cause permanent damage to the body. This is only one reason why it is critical to continue yearly follow-up care with your surgeon and bariatric clinic.

References

  1. https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/
  2. https://asmbs.org/resources/integrated-health-nutritional-guidelines

Jennifer Davis RDN, LD is a Registered and Licensed Dietitian Nutritionist and joined My Bariatric Solutions in December 2019.

B12 Deficiency Affects the Body
jennifer davis

ABOUT THE AUTHOR

Jennifer Davis RDN, LD is a Registered and Licensed Dietitian Nutritionist. She works with bariatric patients on their diet and education for pre and post-surgery diet guidelines. She is always there for her patients at any point in their weight loss journey to answer questions regarding nutrition. She joined My Bariatric Solutions in December 2019.
Read more articles by Jennifer!