Jul 162019

The Hidden Danger of the Vegan Diet : Vitamin B12 Deficiency

The Hidden Danger of the Vegan Diet : Vitamin B12 Deficiency

Before you read further, I want you to know that it is possible to follow a vegan diet and avoid nutritional deficiency. However, it must be done with careful consideration of certain nutrients. It is no secret, that my approach to nutrition is avoidance of dietary restriction unless absolutely necessary. For those that choose, for any reason, to restrict a certain food or food group, you deserve to know how to do so in healthy manner. That is why I am writing this post. I want to specifically address the vegan diet and Vitamin B12 deficiency. I have noticed much work examining a vegan diet and other nutrients, but Vitamin B12 seems to be frequently overlooked.

Destructive Anemia

Pernicious anemia is the deficiency of __________.

This is one of the questions from my Registered Dietitian’s exam years ago. The answer is Vitamin B12 (aka cobalamin). In Latin, pernicious means ruin or destruction. Pernicious anemia, caused by Vitamin B12 deficiency will not only ruin your life, it will eventually kill you.

Poor energy levels are a symptom of early Vitamin B12 deficiency. However, this vitamin also plays a key role in maintaining the myelin sheath. The myelin sheath is a protective covering on our nerves. Think of it like the rubber tubing around the electrical wiring in your house. This covering must remain healthy in order for our body to send and receive appropriate electrical signals. These electrical signals run nearly all of our body’s functions.

As Vitamin B12 deficiency progresses, fatigue is accompanied by tingling and numbness in the arms and legs. Next, balance and coordination are impaired. People experience difficulty walking, and may even fall. If not diagnosed and treated very early, this nerve damage can become permanent. If left completely untreated, the nerve damage continues to the point that death results.

Risk for Deficiency

Those at risk for a Vitamin B12 deficiency include:

  1. Those that follow a vegan diet
  2. Breastfed infants of vegan mothers
  3. The Elderly
  4. History of certain gastrointestinal issues (weight loss surgery, gastric cancer, Crohn’s disease that involves the ileum, long-term use of antacids, and there are others)

For the purpose of this blog post, I will not be addressing items #4. Those conditions fall under Medical Nutrition Therapy, and need to be addressed on an individual basis. If you feel as though you may fall into any of those categories, please seek out a Registered Dietitian.

Sources of Vitamin B12

Vitamin B12 is found in meat, eggs, milk, fish, and poultry. It is bound to the protein of these foods.

The fact that it is found in animal foods is why following a vegan diet increases the risk of the deficiency.

The fact that it is bound to the protein is why those who are elderly are at increased risk for deficiency. As the human body ages, changes in the stomach can make it more difficult for Vitamin B12 digestion and absorption to occur.

Fortification allows for foods other than animal products to contain Vitamin B12. In the USA, grains (like cereals and breads) are fortified. Fortification means that a nutrient is added to a food that:

1) does not contain the nutrient naturally OR

2) the nutrient was removed during processing and later added back in.

Fortification should be viewed more as a supplement rather than a natural source.

There are Vitamin B12 supplements available. However, recent research indicates that these synthetic oral supplements do not as effectively treat Vitamin B12 deficiency as well as naturally occurring sources. Basically, the pills do not work as well as the food. Granted, this research was completed in rats. We are not rats, but this study would not be able to be done in humans for ethical reasons. We are forced to use an animal model. It should also be noted that this study was focused on treating deficiency, not maintaining health. These are very different things. Nonetheless, understanding how to treat disease can give us great knowledge in how to prevent disease.

Another recent study out of Tufts (one the top nutrition schools in the USA), found associations with increased death when certain nutrients are taken in supplement form. Conversely, getting the same nutrients from food was associated with a decreased risk of death. Hmmm….food always seems to be the winner.

Amount Required

The good news is, the Recommended Dietary Allowance (RDA) for Vitamin B12 is only 2.4 micrograms (mcg). This number increases to 2.6 mcg during pregnancy and 2.8 mcg while breastfeeding.

Vitamin B12 is water soluble, so the body cannot store it in amounts considered significant. However, we do know that as long as Vitamin B12 is consumed regularly, deficiency will not develop if an occasional day’s intake falls below the RDA.

This RDA amount looks like 6 oz of steak or two cups of milk. Chicken (6oz) and egg (1) contain less at 0.6mcg. But it has been my experience that most non-vegetarians consume a variety of animal products throughout the day, easily meeting nutrition needs.

For vegans, FORTIFIED nutritional yeast does contain adequate amounts of Vitamin B12. Making this food a helpful addition to a complete vegan diet.

Specifically for a Vegan Diet

I am not one to sugar coat things, and I will be straight with you. If you choose to follow a vegan diet, you will need to get your Vitamin B12 from fortified sources or from dietary supplements. The fortification of foods is concerning for some because that does mean those foods will be more “processed” than others. However, I can assure you, that a little extra food processing is less harmful on long term health than pernicious anemia.

The other aspect of Vitamin B12 deficiency that I will not sugar coat is the risk to exclusively breastfed infants when a mother follows a vegan diet. If a mother’s body is deficient in Vitamin B12, her breastmilk will be also. Because of the of the role Vitamin B12 plays in neurological system development, infants and children who are deficient can suffer irreversible developmental delays. These delays can impact motor skills and intellectual ability. Prenatal supplementation needs to be continued during lactation.

Finally, hear me say, a vegan diet can be followed in a healthful manner, but it does require planning, forethought, and close monitoring of vitamin intake. It is not a diet that should be launched into on the simple recommendation of a friend. It is a diet that does carry risk of significant malnutrition. With appropriate supplementation and meal planning though, it can be a healthy way of eating.