Vitamin B12 Deficiency

Vitamin B12 Deficiency

Vitamin B12 (cobalamin) is necessary  for the human body for various critical functions, such as DNA synthesis, blood cell production, and neurologic function. Vitamin B12 is mainly found in animal products and fortified foods like cereals. Vitamin B12 deficiency is common in elders and can lead to health issues including megaloblastic, macrocytic anemia, Crohn’s disease, and more.

What Are The Common Causes Of Vitamin B12 Deficiency?

One of the main reasons behind vitamin B12 deficiency is insufficient dietary intake.

  • The recommended daily allowance of vitamin B12 for an individual is 4 mcg/day.
  • Vitamin B12 is mainly found in animal products such as shellfish, egg yolks, and organ meat etc.
  • Vitamin B12 deficiency is more common in vegetarians, especially vegans.
  • Foods rich in vitamin B12 are cereals, processed meats, and meal replacement drinks etc.
  • Reduced absorption of vitamin B12 in humans can occur due to lack of intrinsic factor (a glycoprotein secreted by parietal cells within the stomach.) Vitamin B12 combines with intrinsic factor is absorbed in the distal ileum.
  • Approximately 1% of oral vitamin B12 is absorbed passively, even without intrinsic factor.
  • Reduced absorption of vitamin B12 can also occur due to drug interactions or structural abnormalities. Common medications associated with reduced B12 absorption include metformin, isoniazid, colchicine, neomycin, proton pump inhibitors, and H2-blockers.
  • Gastrointestinal surgeries such as ileal resection, gastric bypass or conditions such as atrophic gastritis, achlorhydria etc. can reduce vitamin B12 absorption.

What Are The Signs And Symptoms Associated With B12 Deficiency?

If you have vitamin B12 deficiency, you could become anemic. A mild deficiency might have no symptoms. But if left untreated, it may result in various symptoms such as:

  • Weakness, fatigue, tiredness, or lightheadedness
  • Pale skin
  • Loss of appetite or weight loss
  • Heart palpitations and shortness of breath
  • A smooth tongue
  • Constipation, diarrhea, loss of appetite, or gas
  • Nerve problems like numbness or tingling of hands and feet, muscle weakness, and problems walking
  • Vision loss
  • Mental problems like depression, memory loss, or behavioral changes

How Is Vitamin B12 Deficiency Diagnosed?

The deficiency of vitamin B12 is diagnosed with a blood test and an individual is considered vitamin B12 deficient if:

  • Their B12 levels is less than 200 pg/mL (150 pmol/L).
  • The B12 levels are just around the recommend levels and there are symptoms directing towards B12 deficiency.
  • There are Hematologic abnormalities along with a low hgb (males <13 g/dL [8.07 mmol/L], females <12 g/dL [7.45mmol/L]) and an elevated MCV (>100 fL).

So, get your blood tested if you can identify with any of the symptoms mentioned above. You may also take vitamin B12 supplements to meet your daily vitamin B12 needs. Vitamin B12 supplements are available as hydroxocobalamin, cyanocobalamin, or methylcobalamin in multiple formulations such as oral tablets, sublingual tablets, nasal spray, lozenges, and injections etc. Make sure to consult with your healthcare provider before adding any supplement to your diet.

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