The Importance of Vitamin B-12 & How Your Medications May Be Impacting It (October 2020)
How often do you take a handful of supplements with your medications together? Many of us do not think twice about separating various supplements or medications or mixing medications and supplements.
When I was in school at California State University Northridge (CSUN), my professor and mentor, Dr. Christine Smith, taught a class on drug nutrient interactions. I learned that she was on the board of an organization that wrote a book about this for registered dietitians. I immediately got it and I have kept my eyes and ears open to absorption problems ever since.
Vitamin B-12 is an important vitamin to our bodies. It is involved with neurologic function, red blood cell production, DNA synthesis and a variety of important chemical reactions.
Animal products such as meat, poultry, chicken, and fish all contain Vitamin B-12 as well as fortified cereals and granola bars. When we eat these foods, a person is able to obtain their baseline amount of Vitamin B-12. Fruits and vegetables do not contain this vitamin and, as a result, people who are strict vegans can be deficient in this vitamin. Additionally, individuals who have had bariatric surgery or have had part of their intestines removed are at increased risk for Vitamin B-12 Deficiency. The most common cause of Vitamin B-12 deficiency is a disorder known as Pernicious Anemia, which causes a lack of a substance called the intrinsic factor. As we age, it also becomes difficult to digest and absorb Vitamin B-12.
Acid-lowering medications that an individual would take for gastroesophageal reflux disease (GERD) such as proton pump inhibitors and H2 receptor agonists, can inhibit the absorption of Vitamin B-12. These drugs are more commonly known by their brand names of Prilosec, Protonix, Prevacid, Zantac, or Tagamet and long-term usage of them can inhibit the absorption of this vitamin.
An oral diabetes medication called Metformin also interferes with Vitamin B-12 levels. It is common that your physician will check Vitamin B-12 levels regularly if you are taking these medications.
Research shows that it can take approximately a year for Vitamin B-12 levels to be impacted when taking these medications or when following a vegan diet.
Having sufficient calcium rich foods in your diet is helpful, especially when taking Metformin, and doing so can be very helpful to preventing Vitamin B-12 deficiency.
1. Kim, J.; Ahn, C. W., et al. (2019). Association between metformin dose and vitamin B12 deficiency in patients with type 2 diabetes. Medicine (Baltimore); 98:46.