Plant-based eaters are frequently advised to supplement with vitamin B12. Even meat eaters often fall short on this essential nutrient. What’s the deal? Read below for answers to the most common questions I get:
Where does vitamin B12 come from?
B12 is a water-soluble vitamin that is produced by bacteria found in the soil and in the guts of animals. Plant foods are not reliable sources even though they are grown in soil, since modern farming practices reduce bacteria. Most humans today obtain it indirectly from eating meat. Animal foods contain high amounts because they absorb B12 made by their gut bacteria and accumulate it through manure exposure. Livestock feed is also commonly supplemented with B12.
What does it do?
B12 is involved in DNA synthesis, red blood cell formation, energy metabolism, and central nervous system functioning. Like most essential nutrients, it does a LOT.
How do we become deficient?
Deficiency can happen when our diets are lacking, but also with GI conditions including Crohn’s disease, celiac disease, history of stomach surgery, and even from prolonged use of antacids since stomach acid is required to properly absorb B12. Even with a diet rich in B12 and no relevant health conditions, the aging process can contribute to low levels. As we get older, our bodies produce less stomach acid. This is why it’s important to get your levels tested once a year, regardless of your diet.
What happens if we don’t get enough?
Deficiency can cause anemia and severe neurological disorders. Symptoms range from fatigue and glossitis (a smooth, sore tongue) to memory problems and difficulty walking.
How much do we need?
The RDA for vitamin B12 is 2.4 mcg/day. Most supplements on the market contain around 500mcg. I wouldn’t recommend anything higher because our bodies can only absorb a small portion at a time. If you’re concerned with maximizing absorption, make sure you are taking a sublingual or oral spray form vs. a pill that you swallow.
Because vegans do not consume animal products and their diets are typically high in folate which may mask a B12 deficiency, they should have a reliable source of B12. Plant-based dieters may be able to meet their needs through fortified foods like breakfast cereals and plant-based milks, but supplementing is the safest method. The one I recommend (and use myself) is Garden of Life’s Organic B12 spray. It’s made with the bioactive form methylcobalamin and is easy to use once a day (kind of tastes like candy too!).
