Vitamin B12 is a water-soluble vitamin that is crucial in human body for various functions. It plays a vital role in cell growth and reproduction, protein and tissue synthesis and blood formation. The human body does not produce it, so it has to be absorbed from foods and supplements. Although the human body requires small amount of vitamin B12 for its normal and adequate functioning. Mostly individuals above the age of 50 and those who consume vegetarian diet are deficient in this vitamin. Generally, a healthy diet rich in meat, fish, and dairy products provide a natural source of vitamin B12 required for the body, but it can be deficient in vegetarians and vegans.
Daily Requirement of Vitamin B12
The daily requirement of vitamin B12 varies according to age and is same for both genders, but it increases in pregnant and breastfeeding women, being 2.6 mcg and 2.8 mcg respectively. Infants (up to the age of 6 months) require 0.4 mcg, babies (from 6 to 12 months) require 0.5 mcg, children (between the age of 1 to 3 years) require 0.9 mcg, children of 4 to 8 years of age require 1.2 mcg, children of 9 to 13 years of age require 1.8 mcg and individuals above 14 years of age require 2.4 mcg.
Functions of Vitamin B12
Vitamin B12 plays a vital role in DNA synthesis and production along with cell growth. It plays a crucial role in red cell formation in the bone marrow. Deficiency of vitamin B12 could lead to immature, large and abnormal red blood cells and may cause difficulty in their movement from bone marrow to the blood, thus leading to anemia. It is also important in the formation of myelin sheath around the nerves and also in the transmission of nerve impulses. It also helps in the conversion of homocysteine to methionine. It is also necessary for the maintenance of normal gastrointestinal lining.
Symptoms of Vitamin B12 Deficiency
Vitamin B12 deficiency can affect nervous system, gastrointestinal system, cardiovascular system as well as bone health. The deficiency symptoms include weakness, numbness, tingling, dizziness, memory loss, depression, balance problems, confusion, dementia, fatigue, palpitations, tachycardia, shortness of breath, nausea, lack of appetite, weight loss, diarrhea, constipation, soreness and redness in tongue with loss of papillae, difficulty walking, muscle weakness, irritability, and/or vision loss.
Causes of Vitamin B12 Deficiency
The most common cause of vitamin B12 deficiency is strict vegetarian or vegan diet, as animal foods are the only natural source of vitamin B12. Vitamin B12 deficiency can also be found in people with poor nutrition, infection, cancer, surgery, alcohol, medications (PPIs or other acid-suppressing drugs), exposure to nitrous oxide (during surgery or recreational use), stomach/intestinal problems such as intestinal dysbiosis, leaky gut or gut inflammation, atrophic gastritis or hypochlorhydria (low stomach acid) and/or nerve damage.
The other important cause of vitamin B12 deficiency is pernicious anemia. Pernicious anemia is an autoimmune condition in which the body is unable to make mature red blood cells resulting in the formation of abnormal, large and immature red blood cells. In pernicious anemia, the individual is unable to absorb enough vitamin B12 from food for proper functioning due to lack of intrinsic factor. Intrinsic factor is a protein found in the lining of the stomach and is essential for the absorption of vitamin B12 and folic acid.
Is Vitamin B12 Deficiency Fatal?
Pernicious means “deadly” and initially, it was considered fatal when there was no cure for it, but now with the advent of vitamin B12 supplements and injections this condition can be treated easily. It is no more considered fatal now, as there is an easy cure for it.
Vitamin B12 deficiency can be treated in the form of vitamin B12 supplementation by either capsules, sublingually, nasal sprays or injections.
As vitamin B12 is found only in animal sources, strict vegetarians and vegans should prevent it by taking diet and foods fortified with vitamin B12 such as vecon veg stock, textured veg protein, soya milk, veg and sunflower margarines and breakfast cereals.