Vitamin B-12 crucial for a host of functions
Several factors can jeopardize body’s ability to get enough of nutrient
Some things never change. My daughters still think I drive too slowly. Yet some things do change, especially in the field of nutrition. For example, we used to think that deficiencies of vitamin B-12 were rare except among strict vegetarians or people with an autoimmune disease called pernicious anemia.
New evidence now indicates that if you’re on this list, you may be at risk for a B-12 deficiency: 50 years or older (we can lose the ability to absorb vitamin B-12 as we age), vegetarian or vegan (B-12 is not found in plant foods), take metformin (a diabetes medication that can reduce the body’s ability to absorb B-12), have any type of intestinal disorder or stomach surgery such as gastric bypass (vitamin B-12 needs a well-functioning gut to be absorbed), take anti-acid medicines or aspirin, ibuprofen or similar types of pain relievers (some meds can reduce the ability of stomach acids to digest and absorb B-12).
Although it is only required in micro amounts, vitamin B-12 is vital to the formation of healthy red blood cells and it helps build everything from genetic material (DNA) to hormones and other proteins. Perhaps most notable is B-12’s role in our nervous system, all the pathways that help us to think, move and speak. A deficiency of vitamin B-12 can cause the brain to malfunction and lead to dementia, for example.
Vitamin B-12 (also known as cobalamin because it contains the mineral cobalt) also helps keep our homocysteine levels in check. High levels of homocysteine are associated with inflammation that can lead to heart disease.
For most of us, the most reliable sources of B-12 are animal foods including fish, poultry, meat, eggs, milk, cheese and yogurt. Just three ounces of cooked clams, for example, provide more than a thousand times our recommended intake of vitamin B-12, according to the USDA Nutrient Database.
Other reliable sources include B-12 supplements or fortified foods such as cereals and nutritional yeasts. People with pernicious anemia or other disorders that prevent them from absorbing vitamin B-12 in the stomach may need to rely on regular injections directly into the blood stream.
How much vitamin B-12 we need in a day may also be changing. New evidence suggests the current recommendation may be too low to accomplish all its functions.
In the meantime, here is a hint when talking to your doctor about testing your vitamin B-12 levels. Blood tests for vitamin B-12 may not tell the whole story, according to recent research. According to the National Institutes of Health, additional laboratory tests that include homocysteine and methylmalonic acid values may also be needed to reliably detect low levels of vitamin B-12. Barbara Quinn is a registered dietitian and certified diabetes educator affiliated with Community Hospital of the Monterey Peninsula. She is the author of “Quinn-Essential Nutrition” (Westbow Press, 2015). Email her at barbara@quinnessentialnutrition.com.