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Vitamin B12

by Okanagan Nutrition

While a well planned plant based diet is nutritionally adequate, there are some nutrients to be extra mindful of. One of those nutrients in vitamin B12.

Fun fact!

Neither plants or animal make B12 — bacteria do!

Animals and the food they eat just happen to be contaminated with B12.

Another fun fact!

It is recommended that those over the age of 50, herbivores and omnivores alike, should consider taking a B12 supplement, as the efficiency of absorption decreases as we age.

Why is B12 important?

Vitamin B12 is essential for the formation of red blood cells and for the proper functioning of your nervous system.

This is why B12 deficiency can cause symptoms like tiredness, weakness, numbness and tingling and when severe, depression, confusion and poor memory (yikes)!

B12 deficiency in older adults can actually mimic early symptoms of dementia.

How much vitamin B12 do we need daily?

  • Men and Women 19+, 2.4 mcg/day
  • Pregnant Women 19+, 2.6 mcg/day
  • Breastfeeding Women 19+, 2.8 mcg/day

There is NO upper limit, or maximum dose of Vitamin B12. Any amount of the vitamin that you take over and above what your body can utilize, you simply pee out!

There are zero noted adverse effects from B12 supplements.

Unreliable sources of B12

You may have heard people say that the following foods are good sources of vitamin B12 —

  • Unwashed produce (fruits and vegetables)
  • Mushrooms grown in B12 rich soils
  • Nori (seaweed and algae)
  • Spirulina
  • Chlorella
  • Unfortified nutritional yeast
  • Unfortified fermented foods (tempeh, natto, miso, vegetables)
These foods are are NOT reliable sources of vitamin B12 – meaning, although they MAY contain very small amounts of the vitamin, how much, what form (active or inactive) and if they contain B12 is inconsistent.

The only reliable sources of vitamin B12 are supplements and fortified foods.

Some foods fortified with B12 (always check the label/ingredients list)

  • Meat alternatives (veggie burgers, veggie sausages, veggie ground etc)
  • Store bough milk alternatives
  • Nutritional yeast
  • Cereals

B12 Supplements

Taking a B12 supplement, even if eating fortified foods regularly, is recommended. Because B12 deficiency can have such dire consequences and there are no adverse effects to supplementing … why not!?

As we get older, our ability to absorb B12 from food and supplement, decreases. This is in part due to decreasing stomach acid as well as a decrease in production of intrinsic factor (IF). IF is a substance made by the body to help absorb B12!

There are two types of B12 available:

  • Cyanocobalamin – This is the form of B12 used in most supplements and for fortification of food/beverage. It is synthetic and well absorbed by the body.
  • Methylcobalamin– Is a naturally occurring form of B12 and can be found in both food and supplements. More research needs to be done regarding how effective this form of B12 is at raising blood B12 levels.

Some research shows us that cyanocobalamin may be better absorbed by the body than methylcobalamin.

Supplements can come in liquid or pill form, as well as spray! Choose whichever form works best for you.

Daily Supplements

Aim to take a supplement with at least 25 mcg B12 daily.

People over the age of 50 likely need more because of decreased ability to absorb B12 effectively. If this is you, look for supplements with 250 mcg of B12 daily.

Seniors can need amounts up to 1000 mcg daily to maintain adequate B12 levels.

Weekly Supplements

Don’t want to take a supplement every day?

Aim for a supplement with at least 2000-2500 mcg, two to three times per week.

You may have noticed that the amounts of B12 in supplements is much, much greater than the recommended daily intakes! This is because your body can only actually absorb a very small portion of the B12 ingested.

For example, it is estimated that you only really absorb 10 mcg of B12 from a 500 mcg dose, and this is in people with good absorption!

Concerned about the ‘cyanide’ component of cyanocobalamin?

Consuming something with the word ‘cyanide’ in it, can be scary for some. But, you don’t need to worry. The amount of cyanide found in cyanocobalamin is phsysiologically insignificant.

What’s more is that fruits, vegetables and other plant foods like flax contain small amounts of cyanide as well — and we don’t worry about them!

How to check your B12 levels

Your doctor can order a simple blood test measuring your blood B12! Although it is not the BEST measure of determining your B12 levels, it is the most common. Ask your physician or primary care provider if they can order a methyl-malonic acid (MMA) levels, this is the most accurate blood test we have at measuring B12 levels.

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