Vitamin B12 Deficiency – Causes, Symptoms, and Solutions

Right from the moment I got into the field of fitness and nutrition, I have always been getting to know new things every day. I keep on exploring more and more, and the obsession level is so high that even if I hear anyone drop a single word related to fitness, I find myself drawn to it, sometimes even if it invovles shameless eavesdropping on conversations! This time I overheard a guy in the gym sharing  his problems with one of his buddies there, rather than resort to Google to find his solutions.

As I went deeper (eavesdropping) into the conversation, I came to know that they were discussing about Vitamin B12 , while the other Google guy was explaining to him how he should start having animal food, among a host of other tips, which perhaps were somehow correct! But the story does not end here…of course, being diplomatic, I did not go on to interrupt their conversation and give my unsolicited “gyan” to those two guys, rather I chose to jot down some insights on what exactly is Vitamin B12 and what are its benefits. In this article, I hope to share these very insights with you all.

What is Vitamin B12 and why is it important?

Vitamin B12, one of the eight B vitamins, is a water soluble vitamin also known as Cobalamin. Although it’s a nutrient required in very small amount, it plays a vital role in the life sustaining process inside the cells – whether it be metabolism inside the cells, affecting DNA synthesis, or fatty acid and amino acid metabolism. Vitamin B12 helps make red blood cells, and assists in the normal functioning of the brain and the nervous system. The RDA levels for this vitamin is around 2-3 mg, for an average person in normal circumstances.

Since our body does not make Vitamin B12, we need to get it from animal-based foods or from supplements. Only bacteria and archaea have the enzymes needed for its synthesis.

Sources of Vitamin B12

An important point that I noticed in that interesting conversation that set me off on the Vitamin B12 quest, was that the first guy had been a vegan for some part his life, probably due to some religious compulsions and ‘pujas’ that did not allow him to eat the any non-vegetarian products, neither those from animal sources. That tipped me off to think that maybe there is something that relates Vitamin B12 with the food sources that we opt for.

So the first thing was to make a list of food sources for Vitamin B12:

Proven sources of Vitamin B12 are animal products like meat, fish, eggs, poultry, shellfish, milk, and milk products. This means if someone is not having any these food sources on a regular basis, he/she might be suffering from the vitamin b12 deficiency. Vegans, therefore, are very likely suffering from a deficiency of this important vitamin!

Here’s an interesting infographic representation of the best sources of Vitamin B12:

Foods That Are High in Vitamin B12
Source –

Other Factors that can cause Vitamin B12 deficiency:

One can get Vitamin B12 deficiency if they have certain conditions like –

  • Atrophic gastritis, in which the stomach lining becomes thinner.
  • Surgery in which part of the stomach or small intestine is removed, including the weight loss (tummy tuck) surgery, as well.
  • Long term use of acid reducing drugs – stomach acids help breakdown animal proteins that have Vitamin B12.
  • Someone who is probably a pure vegan (meaning who does not eat any animal products, including meat, milk, cheese, and eggs) or a vegetarian who does not eat enough eggs or dairy products might be affected too.

Symptoms of Vitamin B12 deficiency:

If untreated, vitamin B12 deficiency may progress and lead to symptoms like –

  • Weakness or tiredness
  • Heart palpitation and shortness of breath
  • Pale skin, smooth tongue
  • Constipation, diarrhea, loss of appetite, and gassiness
  • Nerve problems like numbness or tingling, muscle weakness
  • Mental problems like depression, memory loss, behavioral changes, or vision loss


Most pregnant women who have been strict vegetarian even for few years, or the ones consuming low amounts of animal products, are likely to have become Vitamin B12 deficient during pregnancy and lactation thus giving birth to infants who develop clinical and biological signs of B12 deficiency, and/or have low levels of this vitamin in their breast milk thus being unable to cover the deficiency in their newborn through their milk. (This finding needs to be more researched for few more nations though).

Heavy alcohol consumption can be one of the causes for Vitamin B12 deficiency as well.

So, what are the ways to address this deficiency?

  • Most people can prevent Vitamin B12 deficiency by eating enough meat, fish, poultry, and milk products; but if the issue is that you don’t eat animal products, you can change your diet to include Vitamin B12 fortified grains.
  • One can look for plant milks, yoghurts, cereals, spreads, yeast extracts, and nutritional yeast products that are fortified with Vitamin B12. (For a better picture, always check the nutrition labels and supplement details before buying, to make sure B12 is in desired the range)
  • Lastly, one can have a supplement (multivitamin) containing around 10 mg of vitamin B12, one per day.

In extreme cases, for instance if one has pernicious anemia, or a problem with the vitamin absorption, he/she might need to supplement the vitamin by injection. Let’s not get deep into such uncommon cases, and you will need to check with your doctor for any complications at any rate.

The key is as always, to eat healthy, and keep reading up more to increase awareness when it comes to health and nutrition.


Article Credits – Shanu Shashank




Shanu Shashank

Shanu Shashank

Hi All! I’m Shanu. I have been working as a Nutrition Expert with SQUATS for past more than a year and have been able to guide more than 300 people in this short span of time. As a person, I have always been enthusiastic about fitness and sports, with cricket being my first passion. I also have a transformation story. I transformed myself from a 47 kg skinny guy to what I am today, with a much better and muscular physique. During my journey, it was reading that always stood by me and opened my eyes to a deeper awareness of the human body. As a Fitmag Author, it has been my aim to help others through my writings, and with Fitmag serving as the best online platform that makes fitness accessible to EVERY man and woman out there, it becomes easier to reach out to those that need help and support! I love writing as much as I love lifting. And I encourage you to read Fitmag and open your eyes to a better world and a better you!