Vitamin B12 has many roles. It helps convert carbohydrates, fats and proteins into energy. It's required for making our DNA, which means it's especially important during growth. It's also required for red blood cell production, and it helps to maintain the protective coating around our nerves called the myelin sheath.
In some high-protein foods we consume, there's an amino acid called methionine. The breakdown of methionine creates another amino acid by-product called homocysteine. This homocysteine can damage the delicate linings of our arteries, trigger heart disease, and negatively impact bone health. Vitamin B12 helps to get rid of this damaging homocysteine.
The official Recommended Dietary Allowance (RDA) for adults over 14 years of age is 2.4 mcg per day. This may seem like a very small amount! Some recent studies suggest that 4 - 7 mcg may help protect us against high levels of homocysteine.
The Institute of Medicine has concluded, “no adverse effects have been associated with excess vitamin B12 intake from food and supplements in healthy individuals”. In short, there are no known risks to having more vitamin B12 than our body may need.
Fermented foods, sprouts, mushrooms, seaweed, spirulina, meat substitutes, raw plant foods, and breakfast cereals are all possible food sources for vitamin B12. Although some sources say vitamin B12 is present in such foods, these are most often inactive analogues and aren't considered reliable sources for this essential vitamin.
Combining both food intake and supplementation is likely the most effective way to get all of the vitamin B12 that we need.
Types of supplements
When it comes to B12 supplementation, we'll see either the cyanocobalamin or methylcobalamin form. Let's briefly review both.
This form of vitamin B12 has been more extensively researched. It's the most stable form of vitamin B12 and as the name suggests, it contains a teeny amount of cyanide. Cyanide is a potentially harmful chemical but is present to help stabilize the vitamin. This has been a source of hesitation for those purchasing this form of vitamin B12 supplement. However, cyanide is naturally present in nature. For example, 1 tablespoon of flax seeds has 30 times as much cyanide, and this amount has been deemed insignificant by toxicologists. After consuming cyanocobalamin, our body removes and detoxifies the cyanide. It then naturally converts the cyanocobalamin to methylcobalamin, the more active form of vitamin B12. Note that this conversion may be more difficult in those who smoke or have kidney failure. If this is the case, a direct source of methylcobalamin may be best.
This form of vitamin B12 is less stable than cyanocobalamin. Since less research has been done on this form, less is known about its effectiveness. Methylcobalamin also tends to be more expensive, and we know that many factors, such as our age, impact how much we're able to absorb.
How to get enough
Getting enough vitamin B12 is especially important for those of us following a plant-based lifestyle. There are a few ways to make sure our intake is adequate:
Food: consume 3 servings of vitamin B12 fortified foods, with each serving offering at least 2 micrograms (mcg) of vitamin B12. Some foods that may be fortified include plant-based milk, vegan meat substitutes, nutritional yeast, and breakfast cereals. Be sure to read the food labels to determine how much vitamin B12 is in the product, if at all. Note that it's best if these foods are eaten at different times of the day. This is because vitamin B12 receptors can become full with as little as 1.5 mcg doses. In other words, if high amounts of vitamin B12 are taken at a time, our body simply can't absorb it all. As mentioned above, it may be wise to combine both dietary intake with a supplement, as the amount of vitamin B12 in these foods can vary.
Daily supplementation: each day, take a cyanocobalamin supplement that offers at least 25 mcg of Vitamin B12. When taking a multivitamin supplement, be sure to check the label as this amount or more may be provided. Some experts suggest that a larger dose of 500 - 1000 mcg per day may be required for adults over the age of 65 due to the reduced ability to absorb vitamin B12 from foods.
Biweekly supplementation: twice a week, take a cyanocobalamin supplement that offers 2000-2500 mcg of vitamin B12. Although our daily needs for vitamin B12 is much less than this, the body only absorbs a fraction of what's offered by a supplement. This dose is higher than suggested for daily supplementation, because the less frequently vitamin B12 is taken, the higher the dose we need is.
Commonly asked questions
What supplement type should we take? Liquid supplements, tablets that dissolve under the tongue, as well as regular tablets to swallow or chew are all suitable.
What if we take too much? When we take larger doses, the body only absorbs a fraction of what's offered because the receptors become full and can't absorb any more. With this in mind, there's no concern with taking too much. Additionally, vitamin B12 is a water-soluble vitamin, meaning any extra we have above and beyond what our body needs will simply be excreted in our urine.
What if we miss a dose? The body is phenomenal at re-absorbing vitamin B12. It shouldn't be a cause for concern if we happen to go a period of time without supplements. For those of us who've been vegan for a few months and haven't been supplementing, now's a great time to start!
What do deficiency symptoms look like? Short-term deficiencies can be remedied. Long-term deficiencies on the other hand can cause irreversible damage. Early symptoms of deficiency include weakness, fatigue and mood changes. These can be easily confused for other causes aside from vitamin 12 deficiency, so it's important to supplement regardless. Avoid relying on symptoms to indicate if intake is low if possible.
Doesn't our body make vitamin B12? Indeed, our body has been thought to make some vitamin B12 naturally. This amount isn't enough to meet our needs, though, and tends to be made too far down in our digestive tract to be absorbed,
- The recommended intake of vitamin B12 for adults is 2.4 mcg per day. For older adults, the recommendations are much higher.
- Foods alone are not reliable sources of vitamin B12. Supplementation is often recommended to be combined with food intake.
- Vitamin B12 supplements come in the form of cyanocobalamin and methylcobalamin. Choosing which form to take will depend on your needs, lifestyle, and current medical conditions.
Discussion & Rating
Hi PUL team,
I have only found supplements with 1000 MCG, and it doesn't seem to be recommended to cut pills in half unless noted. If trying to follow daily recommendations, would I be better off skipping step 2 AND just doing step 1 (food) and step 3 (biweekly)?
Thank you for such a valuable information!
I was told by my dermatologist (and since then reading about it) that B12 can cause acne, which it might had been my case. I stopped taking the supplement a couple of years ago + follow an acne treatment and the acne improved, but my latest blood test shows very low B12 :(
Have you also read/research about it? What is your take on it?
Hello pick up limes!
I’m following you few years and cook with you very often!
You had give me a lot of inspiration to cook and live healthier way. So I an kind of your fan:)
I am having a lot of questions these days when i became a mother how to grow my vegan child and how to make my family healthy. So I started to searching in internet an information about which products I have to chose and faced with different information about supplements that I have to give to my child and husband and me. There is an information that Baby after 1-3 years has be taken 0,9 or 1 mcg every day, some websites talks that 2.5-5 per day or 250-300 per week (I guess it’s wrong info)
So I decided to open your website and find out what you thinking about it. But I didn’t find about baby supplements. So I want to ask you how much should I give it to my child if all supplements goes like 1000 mcg per one click of spray) and how much we shoul take with husband ? Should I give and take other supplements for ourself and kid like dha iodine and d3 ?
Thank you so much for answering!
Hi PUL team! Thanks for all your great and valuable content! I have a question regarding B12 supplements. I’m taking one that has 2mcg and the dosis is to take one daily. So should I take more than one per day (ie 1 with every meal) to get closer to the required B12 absorbed?
I just started taking vitamin B12 and this information is sooo amazing!
Thank you very much, you guys definitely make our life much easier :)
Hi Sadia, thanks for the great article. You are very inspiring and I live your videos. I had a question regarding B12 supplement. Do you know if the supplements are made from non-animal sources? Thank you.
Hey PUL team, Thanks for the article! Very insightful!
Thank you! I just started to become vegan this year. This clears my mind as to am I taking the right dose or type of b12.
Hi Sadia, I got my B12 level tested and is 114 pgml and us indicated a little low. M a female 31 yes of age .
My doctor has prescribed 1500 mcg of mecobalamin. To be taken daily.
Can you comment on that if that's fine or is more or share I reduce the dose to 1000mcg.
Thank you for a very useful helpful article!
I have been wondering if I should buy a B12-supplement, but I have been afraid to take B12 in case any excess of it would be stored in my body. I am not fully plant based yet, but on my way.
I love your blog and your YouTube channel. I know I can trust the information you give since you are a certified dietist. It is otherwise quite a jungle out there on Youtube regarding what is considered healthy vegan food. Keep up the good work!
Is there any brand of vitamins/supplements you recommend?