Nutrition focus: Vitamin B12


The next nutrition focus is the B vitamins or often thought of as B-complex.  We will start with one of the most active B vitamins ~ B12.

Vitamin B12 is involved in the maturation of red blood cells and with folate (vitamin B9) helps iron work better.  B12 helps the body utilize carbohydrates as fuel which is glucose.  B12 is necessary for nerve cell health, for the development of the nervous system and the production of DNA and RNA which is the body's genetic material.  B12 combined with folate produces S-adenosylmethionine (SAMe) which is involved in immune function and mood stabilization.

Vitamin B12 is absorbed by attaching to a protein called intrinsic factor which is found in the acidic environment of the stomach. Absorption of vitamin B12 requires the presence of stomach acid. Vitamin B12 absorption is enhanced by the chewing of foods rich in B12 or by chewing supplements.  B12 is made by gut bacteria but this cannot be absorbed into the body as there is no intrinsic factor or acidity in the large or small intestine.  Small amounts of B12 attach to intrinsic factor receptor for absorption and the remainder of the ingested B12 is excreted from the body.  The receptors can remain saturated for a few hours before becoming available to again absorb B12.

B12 Deficiency

  • Causes anemia
  • Fatigue
  • Shortness of breath
  • Neurologic symptoms such as balance issues, muscle weakness, visual disturbances
  • Dementia
  • Mood disturbances
  • Elevated homocysteine, an amino acid associated with increased risk of stroke and heart attacks

People at risk for B12 deficiency

  • Gastrointestinal disturbances e.g. Crohn's disease, pancreatic disease, H. pylori infection
  • Eating disorders
  • HIV infection
  • Elderly status as often they have lower amounts of stomach acid and they eat less overall
  • Taking medications that reduce stomach acid e.g. proton pump inhibitors
  • Breast fed infants of mothers who eat a vegan diet
  • People who eat a vegan diet

Foods that naturally contain Vitamin B12 are all of animal origin. There are some B12 look-alike chemicals in algae and tempeh but these are not real B12 and they are not available in the body for absorption. There are no plant foods that have B12 other than fortified foods and supplements which are critical for people at risk for B12 deficiency.

Foods with B12

  • Red meat, poultry, fish and eggs
  • Milk, yogurt, cheese
  • Fortified grains - many breakfast cereals contain B12 
  • B12 enriched soy milk
  • Fortified brewer or nutritional yeast - check labels as natural yeast does NOT contain B12.  It must be added.
  • B12 vitamin supplements

The easiest way to obtain B12 in the diet is with small amounts of foods of animal origin.  However, we don't need a lot of B12 so can still have an overwhelmingly plant based diet.  If not eating any animal derived foods, the most efficient way to ensure B12 absorption is to take a B12 supplement but also to eat fortified foods twice daily about 4 hours apart.  This takes advantage of how B12 is absorbed and allows the maximal amount of it to be absorbed.

Daily recommended B12 from supplements is about 25-100 micrograms daily.  B12 must be taken daily as it is a water soluble vitamin that is not stored adequately in our bodies. 

Join us for an interesting Nutrition and Yoga for Emotional Health workshop on Saturday, February 10 at 10:30am at the Whole Yoga & Wellness studio.  We will be talking about the role of B12 in mental health.  It will be a great workshop as we will learn and move!

To learn more and/or register, go to  You will also have the opportunity to download a great home remedy resource, The Wholistic Medicine Cabinet by entering your email and if you are local in Columbus, Ohio, you can get 25% off any class or workshop.