2. Do Vegans Need to Take a Vitamin B12 Supplement?
Vegans must supplement with vitamin B12. Not doing so can have severe consequences. It’s essential for maintenance of the nervous system and the production of DNA (and consequently for cell division).
Especially relevant, a deficiency can lead to Megaloblastic anemia and neurological damage. Symptoms include depression, mental uncertainty, blurred vision, memory loss, and paralysis. While it’s reversible with therapy, the neurological damage may not be.
Ginny Messina, MPH, RD, a registered dietitian specializing in vegan nutrition, talks about the signs of deficiency:
Although anemia usually occurs first, this isn’t always the case. One problem is that another B vitamin, folate, can “mask” anemia due to a deficiency. Folate steps in and prevents anemia, but it can’t prevent nerve damage. So, if your diet is rich in folate but low in vitamin B12, nerve damage can actually be the first symptom.
A Blood level of 200 pg/ml (picograms per milliliter) of this vitamin is okay. It’s enough to prevent anemia and nerve damage according to Messina, but levels should be above 400 pg/ml for optimal health.
How Much Vegan B12 Do You Need?
Of all the frequently asked vegan health questions, this one might be the most important. That’s because there is no vegan food source of vitamin B12. You might read that seaweed, mushrooms, or tempeh are good sources, but these claims are unfounded. These foods contain inactive B12 analogs. The compounds are similar but without vitamin activity. Relying on these foods to meet daily allowances is dangerous and can raise the risk for deficiency.
Therefore, it is critical to include fortified foods or supplement in your diet.
Recommended Daily Allowance (RDA) of Vitamin B12
The Recommended Daily Allowance (RDA) for Vitamin B12 is 2.4 mcg per day. But Messina recommends 4-7 mcg a day to prevent potential deficiency symptoms.
Figuring out appropriate dosages of B12 gets tricky…because of the way this vitamin is absorbed. Small amounts of vitamin B12 attach to receptors for absorption. These receptors quickly become saturated by just 1 to 2 mcg…and they stay that way for several hours. If you ingest a big dose…from a supplement you can still absorb a little bit of the excess that can’t attach to receptors. But absorption of that extra amount is just a very small percentage of the total.
It is easy to meet the requirements for this nutrient by consuming several small servings of fortified foods throughout the day. However, if you’re relying on a supplement to meet your needs, you’ll need a lot more.
Messina suggests the following options:
- Eat two servings per day of foods fortified with at least 2 to 3.5 mcg of vitamin B12 each, consumed at least 4 hours apart for optimal absorption or,
- Take a daily supplement providing 25 to 100 mcg of (cyanocobalamin) vitamin B12 or,
- Take a supplement containing 1,000 mcg of (cyanocobalamin) vitamin B12, twice per week.
Cyanocobalamin or Methylcobalamin?
Cyanocobalamin is the form of Vitamin B12 that is recommended by vegan nutrition experts. However, many brands contain methylcobalamin instead. Before the vitamin can do its job, the body must convert cyanocobalamin into methylcobalamin.
So why not just take methylcobalamin directly? According to Messina, it’s not because one is better than the other. It’s because there’s more reliable information about appropriate dosage levels. For that reason, only supplements containing cyanocobalamin are featured.
If you are taking a supplement that contains methylcobalamin in place of cyanocobalamin, Messina recommends taking 1,500 mcg per day.
Shop for Vegan B12 Sublingual Tablets
Without a doubt, the easiest way to meet the RDA of Vitamin B12 is to take a sublingual tablet. These are tablets that you place under your tongue and allow them to dissolve. The nutrients are then absorbed into your body through the blood vessels in your mouth.
The following supplements are vegan and contain Vitamin B12 in the form of cyanocobalamin: