5 Facts About Vitamin B12

Vitamin B12 plays a variety of roles in your body such as producing red blood cells and providing energy. Read on more to know about its functions, side-effects, requirement, and sources.

July 13, 2022

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Vitamin B12, or cobalamin, is an essential vitamin as your body cannot produce it and must be obtained externally through food sources or supplements. Cobalamin is important for nerve, heart, red blood cells, and joint health. Let’s learn more about this supplement

It is important for your body

Some of the important functions of vitamin B12 in your body are:

  • Maintaining the health of the eyes and preventing macular degeneration

  • Supporting the health of bones

  • Producing red blood cells

  • Preventing degeneration of the nerve cells

  • Improving mood and memory

  • Supporting the healthy development of the fetus


Lower levels of vitamin B12 can be harmful

Although vitamin B12 is present in a variety of animal food sources, it is not so commonly found in plant-based food items. So, individuals on a strict vegetarian diet are often seen to have vitamin B12 deficiency. In addition, the elderly, individuals with gastric surgery, those consuming antacids for a longer duration, and people on metformin, are at a higher risk of vitamin B12 deficiency. Some of the common symptoms include:

  • Yellow or pale skin

  • Tingling numbness in extremities

  • Weakness

  • Recurrent mouth ulcers and inflammation of the tongue

  • Vision disorders

  • Breathlessness

  • Dizziness

  • Difficulty in maintaining balance while walking

  • Mood changes

Even higher levels of vitamin B12 are harmful

Higher doses of vitamin B12 can have the following side effects:

  • Itching

  • Diarrhea

  • Skin rash

  • Nausea

  • Vomiting

  • Headache

Recommended daily allowance

The recommended dose depends on age and gender and is as mentioned below (Table1):

Table 1: Recommended daily allowance based on age and gender


Recommended daily allowance

0-6 months

0.2 g/day

6-12 months

0.2 g/day

1-9 years

0.2 g/day

10-17 years (boys)

0.2 - 1 g/day

10-17 years (girls)

0.2 - 1 g/day

Adult men

1 g/day

Adult women

1 g/day


1.2 g/day


1.5 g/day

Vitamin B12 is not commonly present in plant sources

Some of the food items that have a high content of vitamin B12 are:

  • Clams

  • Beef

  • Sardines

  • Eggs

  • Milk and dairy products

  • Fortified cereals

  • Tuna

  • Salmon

Interesting fact:

Vitamin B12 is made by certain microorganisms and thus plants do not contain B12!!

We have started an A-Z, blog-series on nutrients, covering all your vitals in one place! Write to us at info@labelblind.com if you would like a specific nutrient of interest to be covered, we would love to keep that as our priority!


National Institute of Nutrition. Indian food composition tables




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Rashida Vapiwala (Founder at LabelBlind®, Food Label Specialist, Ph.D (Food Science and Nutrition))

Rashida is passionate about solving problems for the food industry using technology. She loves creating tech-led solutions in the space of Nutrition.

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