Vitamin B12 Deficiency and the Vegan Diet

Definition, Signs, and Natural Treatment

Overview

In this article, we will explore one particular concern that gets often brought up with the vegan diet – the risk of vitamin B12 deficiency.

Every year, the number of people who adopt the vegan diet increases. Experts attribute this phenomenon to the health benefits of eating fresh veggies and fruits, while eliminating processed foods.

According to one study, 9.6 million Americans have adopted the vegan lifestyle, which translates to around 3% of the population.
As expected, the rapid increase in the number of vegans raised some concerns. This includes the safety of excluding all animal products and the risk of developing nutritional deficiencies.

 

The physiological role of vitamin B12

Vitamin B12 (a.k.a., cobalamin) is a water-soluble compound. It plays a vital role in DNA synthesis and the production of new red blood cells.
Cobalamin is indispensable for the production of new red blood cells, which transfer oxygen to different tissues. Low levels of vitamin B12 causes a type of anemia that primarily presents with fatigue.

Researchers found that vitamin B12 boosts the basal metabolic rate (BMR). This allows your body to generate adenosine triphosphate (ATP) more efficiently.
Sufficient amounts of vitamin B12 also:

  • reduces the risk of age-related macular degeneration
  • improves symptoms of psychiatric disorders (i.e., depression)
  • prevents birth defects.

The list of vitamin B12 benefits does not end here, since this compound is involved in a myriad of physiological processes.
Normally, we can find vitamin B12 in meats, fish, eggs, and dairy products. For this reason, many vegans are concerned about whether they are getting sufficient amounts of vitamin B12 through their diets.

Vitamin B12 deficiency

The primary organs affected by vitamin B12 deficiency are the nervous system and the circulatory systems.

Unlike iron deficiency, which leads to microcytic anemia (i.e., the red blood cells become smaller), vitamin B12 deficiency precipitates megaloblastic anemia. The latter is characterized by the production of large red blood cells that do not function properly.

Researchers also found that low levels of B12 increase the risk of dementia, depression, paranoia, and certain behavioral changes.

Unfortunately, when the nerve cells get damaged, there is no current therapy that could effectively reverse the process.

Mild symptoms of vitamin B12 deficiency include:

  • Tiredness or fatigue
  • Weakness
  • Constipation
  • Loss of appetite
  • Weight loss
  • Balance problems
  • Confusion
  • Poor memory
  • Soreness of the mouth or tongue
  • Numbness and tingling in peripheral extremities (i.e., hands and feet)

By far, the most devastating adverse effect of vitamin B12 deficiency is birth defects, since these are usually irreversible.
Studies suggest that the prevalence of B12 deficiency ranges between 1.5% and 15% of people in the US. The incidence is even higher in vegans.

Vitamin B12 deficiency and the vegan diet - Diet Zest article

The vegan diet and vitamin B12

In general, unwashed organic produce (e.g., mushrooms grown in B12-rich soils, nori, spirulina, chlorella, nutritional yeast) have vitamin B12.

Some vegans believe that including some of these plant foods in their diets means they don’t have to worry about vitamin B12 deficiency. However, research is not aligned with this belief.

Furthermore, the plant foods that seem to naturally contain vitamin B12 might not be active in humans.

To add to the argument, there is no scientific evidence that recommends depending on unwashed organic produce for vitamin B12.

According to studies, people who follow a vegetarian or vegan diet have a higher risk of developing vitamin B12 deficiencies, relative to those on a regular diet.

The appropriate vitamin B12 dosage

For adults, the daily recommended intake is 2.4 micrograms (mcg) per day. This number changes slightly during pregnancy (2.6 mcg) and breastfeeding (2.8 mcg).

The recommended daily intake of vitamin B12 for vegetarians and vegans is similar to individuals on a normal diet.

To reach these daily recommendations, vegans must consume large amounts of B12-fortified foods or take dietary supplements.

However, if you are under the age of 50 years and following the vegan diet, it is very challenging to meet the RDI of 2.4 mcg per day.

You see, taking vitamin B12-fortified foods may not be enough. For instance, the cobalamin found in nutritional yeast is light-sensitive, which means it might degrade if you buy the product from a store that uses clear plastic bags.

In one review paper, scientists reported that 86.5% of vegetarians have abnormally low levels of vitamin B12.

Unfortunately, there are no official RDI guidelines for vegans and vegetarians.

However, one study suggested that taking 6 mcg of vitamin B12 per day might be appropriate to keep normal serum levels.

For all the reasons listed above, vegans might not be able to reach the recommended daily intake. This is true, even when consuming B12-fortified foods. To compensate for this, you may want to take a daily supplement that provides 25–100 mcg of cyanocobalamin. Alternatively, a weekly dosage of 2,000 mcg.

If you still have concerns about supplement intake, you can always test your serum levels of vitamin B12. This will allow you to tailor your dietary/supplement needs.

You should also keep in mind that the absorption of vitamin B12 becomes less efficient with age. In fact, the Institute of Medicine recommends that individuals over the age of 51 start consuming fortified foods. They also suggest taking B12 supplementation regardless of whether you are vegan or not.

Disclaimer: before taking vitamin B12 supplementation, you may want to speak with your primary care physician to ensure that it is safe. Your doctor may also order some blood tests to measure serum levels of B12.

Takeaway message

The vegan diet provides a myriad of health benefits to the human body. It optimizes your cardiovascular system, digestion, cognitive functions, and more!

Awareness of the potential nutritional deficiencies associated with this diet will allow you to be one step ahead. This also helps prevent unnecessary complications.

Hopefully, this article managed to shed some light on the importance of supplying your body with vitamin B12.

You can also check out Vegan Diet - An Easy Guide for Beginners and our Personalised Grocery List service.

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