Vitamin B12 as the name implies is part of the B complex of vitamins. How much of each vitamin you need depends on your age and gender. Other factors, such as pregnancy and illness are also important. Women who are pregnant or breast-feeding need higher amounts.

B12 also known, as cobalamin, is a water-soluble vitamin that helps in the functioning of the brain, the nervous system and the formation of  blood cells. It provides the nutrient involved in making DNA, a genetic material found in all cells. Vitamin B12 helps prevent a type of anemia called megaloblastic anemia that makes people tired and weak. The vitamin is the largest and most structurally complicated vitamin and can be produced industrially only through bacteria. Vitamin B12 present almost exclusively in animal foods. Vitamin B12 is the only vitamin that contains a metal (cobalt). Probably, the most important thing to know about vitamin B12 is a simple one. If you regularly eat animal foods, you probably get enough dietary vitamin B12. If you are vegetarian, or especially if you are vegan, you will need to go out of your way to obtain this vitamin.

What foods provide vitamin B12?

The best way to consume Vitamin B12 is through animal foods. The animals are able to save vitamin B12 in their body, which passes on. Plant foods have no vitamin B12 unless they are fortified. The body absorbs animal sources of vitamin B12 much better than plant sources. Non-animal sources of vitamin B12 vary in their amount of B12 thus; it cannot be a reliable source of the vitamin.

You can have the recommended amounts of vitamin B12 by eating a variety of foods including the following:

  • Beef liver and clams (which are the best sources of vitamin B12).
  • Fish, meat, poultry, eggs, milk, and other dairy products (which also contain vitamin B12).

A single serving of seafood per day of many types of seafood will meet or exceed your daily intake requirement. The best way to meet your body’s vitamin B12 needs is to eat a wide variety of animal products.

Supplemental vitamin B12 found in the following:
  • Most multivitamins have vitamin B12.
  • Vitamin B12 is better absorbed when it is taken with other B vitamins such as, niacin, riboflavin, vitamin B6, and magnesium
  •  Injection or as a nasal gel is the  way to be given a prescription form of vitamin B12
  • Vitamin B12 is also available in a form that dissolves under the tongue (sublingual).
How much vitamin B12 do I need?

The amount of vitamin B-12 you need each day depends on your age. Average daily-recommended dosage differs from age to age. The list below demonstrates the intake in micrograms (mcg):

Dietary Reference Intakes for vitamin B-12:

Infants (adequate intake)

  • 0 – 6 months: 0.4 micrograms per day (mcg/day)
  • 7 – 12 months: 0.5 mcg/day


  • 1 – 3 years: 0.9 mcg/day
  • 4 – 8 years: 1.2 mcg/day
  • 9 – 13 years: 1.8 mcg/day

Adolescents and Adults

  • Males and females age 14 and older: 2.4 mcg/day
  • Pregnant teens and women: 2.6 mcg/day
  • Breastfeeding teens and women: 2.8 mcg/day
Symptoms of Vitamin B12 Deficiency

A lack of vitamin B12 occurs when the body does not get or is unable to absorb the amount of vitamin that the body needs. This deficiency leads to vitamin B12 deficiency anemia. A mild deficiency may cause only mild, if any, symptoms. Untreated Anemia causes:

  • Weakness, tiredness, or light-headedness
  • Rapid heartbeat and breathing
  • Pale skin
  • Sore tongue
  • Easy bruising or bleeding, including bleeding gums
  • Stomach upset and weight loss
  • Diarrhea or constipation
Causes of Vitamin B-12 Deficiency

There are a few reasons on why you might have B-12 deficiency

  • When your stomach lining has been thinned, Atrophic gastritis.
  • Body is having a hard time absorbing vitamin B12, Pernicious anemia.
  • Those who have had gastrointestinal surgery, such as weight loss surgery, lose the ability to absorb vitamin B12.
  • Crohn’s Disease *conditions affecting the small intestine.
  • Celiac Disease ( Bacterial growth or parasite).
  • Heavy drinking.
  • Graves’ disease  (Immune system disorders).
  • Lupus.
  • Long-term use of acid-reducing pills.
  • People who follow a vegetarian or vegan diet should try to eat vitamin B12-fortified foods or talk to their doctor about taking B12 supplements.
  • Babies born to mothers who are vegetarians may also have a lack of vitamin B12 in their system.
  • Many people over age 50 lose the ability to absorb vitamin B12 from foods.
  • Loss of balance.

What are the risks of taking vitamin B-12?

  • The side effects and risk of vitamin B12 are rare, if taken at normal doses, side effects are rare. High doses may cause acne. Allergies to vitamin B-12 supplements can cause swelling, itchy skin, and shock.  
  • Drugs for acid reflux, diabetes, and other conditions may make it harder for your body to absorb vitamin B-12.
Preventing Deficiency Problems

Most people can prevent vitamin B12 deficiency by eating enough meat, poultry, seafood, dairy products, and eggs.

If you do not eat animal products, or you have a medical condition that limits how well your body absorbs nutrients, experts recommend taking a B12-containing multivitamin and eating breakfast cereal fortified with vitamin B12.

If you are using vitamin B12 supplements, let your doctor know, so he or she can make sure they will not affect any medicines you are taking.

Vitamin B12 provides the necessary nutrient for your body and with the right dosage and care it helps keep the body healthy.

It is recommended that you talk to your health physician (doctor, registered dietitian, pharmacist) about your interests in Vitamin B12, ask questions and use the dietary supplements which are most suitable for your overall health.

Share this Post