Vitamin b12 deficiency causes

vitamin b12 deficiency causes:

Vitamin B₁₂ is present in many forms and contains the mineral cobalt. The compounds with vitamin B₁₂ activity are collectively called “cobalamins”. Vitamin B₁₂ or cobalamin, encompasses a number of forms comprising cyano-, methyl-, deoxyadenosyl- and hydroxy-cobalamin. The cyanocobalamin form is used in supplements and is found in trace amounts in food (1).

vitamin b12 deficiency causes include malabsorption of vitamin B₁₂ rather than lack of dietary vitamin B₁₂. Consuming inadequate dietary vitamin B₁₂ is however common in the elderly, vegans or lacto-ovo vegetarians with poor diets.

How much vitamin B₁₂ do we need?

The recommended dietary allowance (RDA) of B₁₂ for adults is 2.4 micrograms. The recommendation increases for women to 2.6 micrograms during pregnancy and 2.8 micrograms during lactation.

How is vitamin B₁₂ absorbed?

In food vitamin B₁₂ is bound to protein, hydrochloric acid released by the stomach is needed to break the bond. The free vitamin B₁₂ can now interact with R proteins released by stomach cells. Once in the intestine cobalamin is released from R proteins and it binds to intrinsic factor to facilitate its absorption in the intestine. Improper functioning of which would become one of the vitamin b12 deficiency causes (1).

vitamin b12 deficiency causes and conditions 

Are you a vegetarian?

If you are a strict vegetarian then you might be at risk of being vitamin B₁₂ deficient compared to non-vegetarians and lacto-ovo-vegetarians. The only sources of vitamin B₁₂ are animal foods. Plant foods do not have any B. Therefore, eating only foods from plant sources and without taking any vitamin B₁₂ supplements are the most prominent vitamin b12 deficiency causes in this case(2).

Surgery of the stomach

The absorption of vitamin B₁₂ depends on R proteins and intrinsic factor secreted by the stomach. These proteins need to interact with vitamin B₁₂ so that the stomach and small intestine can absorb it. If for some reason these proteinsare not secreted, it indicates one of the vitamin b12 deficiency causes.

For example, deficiency may occur in case of surgery of the stomach where part of it is removed or stapled.  There would be decrease in the cells that produce R proteins and intrinsic factor which in turn leads to reduction in the absorption of vitamin B₁₂. vitamin b12 deficiency causes pernicious anaemia also synthesis of intrinsic factor is reduced thereby lowering vitamin B₁₂ absorption.

Older people

Older people because of gastritis atrophy are at an increased risk of a vitamin B₁₂ deficiency. Their stomachs lose the ability to make hydrochloric acid as they get older and becomes one of the major vitamin b12 deficiency causes. Stomach acid is essential to free the vitamin B₁₂ in food as it is bound to protein so that it interacts with R proteins and intrinsic factor and finally gets absorbed.

Because of the decrease in the amount of hydrochloric acid in the system it might lead to increase in the growth of normal intestinal microflora which probably consumes vitamin B₁₂. This situation leads to vitamin b12 deficiency causes, further reducing the amount of vitamin B₁₂ available to the body for absorption (3).

Gastrointestinal disorders

People with stomach and small intestine disorders like celiac disease and Crohn’s disease may be unable to absorb enough vitamin B₁₂ from food and add to the vitamin b12 deficiency causes.

Though it is very important that pregnant women and elderly people get adequate vitamin B₁₂, it is necessary for all throughout life to lead an optimally healthy life.

References

1. O’Leary, F. and Samman, S. (2010) Vitamin B₁₂ in health and disease, Nutrients. Vol. 2(3). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257642/

2. Wildman, R. (2009) The Nutritionist-Food, Nutrition, and Optimal Health, Vitamins Are Vital Molecules in Food, 197. Routledge, Taylor and Francis Group. Second Edition. New York and London.

3. Vitamin B₁₂ Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/Vitamin B₁₂ -Health Professional/