Best Vitamin B12 Supplements UK 2022 Buyer’s Guide

If you are a strict vegetarian, over age 50, or taking medication that reduces the body’s production of stomach acid, you may be among those people who need an extra dose of vitamin B12. This essential nutrient—also called cobalamin because it contains the metal cobalt—comes from the food you eat (primarily from animal products), and is essential for maintaining healthy nerve cells and red blood cells, and for producing deoxyribonucleic acid (DNA), the genetic material in all cells.

This is the most recently discovered of the B vitamins, this essential nutrient is involved in the formation of red blood corpuscles, the production of DNA, and the manufacture of myelin sheaths that protect nerves. Your body also needs B12 to use another B vitamin, folate and to metabolize food. B12 deficiency is often caused by a condition called pernicious anaemia, which can lead to weakness and tingling in the extremities, among other symptoms.

Also, some vegans—whose diets exclude animal products can develop deficiency. Rich dietary sources include meats, fish, and dairy products. As a dietary supplement, vitamin B12 is sold in capsule form and is included in most multivitamins. Injections are available in doctor’s offices.


Best Vitamin B12 Supplement UK

Table of Contents


The Composition and Value of Vitamin B12

Vitamin B 12 is one of the components of the vitamin B  complex, which is composed of eight vitamins. This includes thiamin or B1, riboflavin or B2, niacin or B3, pantothenic acid or B5, picrotoxin or B6, biotin or B7, folic acid or B9, and cyanocobalamin or B12. These eight vitamins are the “official vitamins” of the B complex.

There are also four “unofficial vitamins” called the four cousins. These include PABA (Para-aminobenzoic Acid), choline, inositol, and lipoic acid. Technically these are not vitamins because our bodies make them. As a result, there is no governmentally approved recommended daily allowance (RDA).

Vitamin B12 is the largest and the most complex of all of the vitamin molecules. B12 differs from the other vitamins of the B complex because it is the only vitamin that contains an inorganic element, the mineral cobalt, and microorganisms that synthesize the B12. It has been called the most essential nutrient for helping the mind retain its acuity.

Further, vitamin B 12, like many other members of the B complex, is not a single substance. Rather, it consists of several closely related compounds with similar properties. Itis the only vitamin that requires a specific gastrointestinal tract secretion for its absorption. This is called its intrinsic factor. This vitamin differs also in its absorption rate, in that it takes three hours to be absorbed in the small intestine, while the other vitamins take only a few seconds or minutes to be absorbed. Vitamin B 12 cannot be synthesized by plants or by animals.

The B complex, as well as each of its components, have multiple and varied functions. In our review and study, we will focus our attention only on vitamin B12, trying to understand the multiple advantages of this frequently overlooked vitamin. We think that we will discover in our study that B12 has many useful properties that are either unknown or overlooked by many people, including physicians.


Top 5 Best Vitamin B12 Supplements in the United Kingdom 2022


What it Does

Supplementation with B12 is important for treating a deficiency of this vitamin, which can cause pernicious (persistent) anaemia, nerve damage, and brain damage. It may also boost the number of sperm cells in men with abnormal sperm production and when combined with folic acid, may reduce the risk of cardiovascular disease. Weak or preliminary evidence suggests a role for B12 in treating Alzheimer’s disease, multiple sclerosis, and tinnitus. Preliminary evidence also suggests that B12 may play a role in the treatment of cataracts. Low B12 levels have been found in people with recurrent canker sores (aphthous ulcers).

Doctors treat pernicious anaemia with injections of B12. Some sufferers of chronic fatigue syndrome supplement their diets with high doses of this vitamin. It used to be fashionable for rock stars and other celebrities to get B12 shots when they were hungover, sick, or just plain pooped; athletes sometimes use the injections to boost power. Like the other B vitamins, B12 is often included in so-called stress-formula capsules.

How it Works

Vitamin B12 is attached to proteins in your food. During digestion, stomach acid releases the vitamin so that it can combine with a substance called intrinsic factor, which allows the vitamin to be absorbed and used by the body. B12 helps nerve cells to function properly and works with folate (vitamin B 9 ) to reduce levels of homocysteine in the blood (high levels of homocysteine are believed to increase the chances of developing heart disease and stroke). B12 is also involved in the body’s production of DNA and S-adenosylmethionine.

What Are the Functions

It functions as a methyl donor. Its functions and properties are in many aspects similar to folic acid. As a methyl donor, It is a compound that carries and donates methyl groups (a molecule of one carbon and three of hydrogen) to other molecules, including cell membranes and to the neurotransmitters.

Vitamin B 12, as a methyl donor, is also an important factor in the metabolism of homocysteine as well as in nerve function, immune function, genetics and in energy metabolism. It participates in every methylation reaction in the body including cell division. It shares a special relationship with folic acid in this essential function—the cell division.

B12 is active in all cells, especially as coenzymes in the cells of bone marrow, central nervous system, and gastrointestinal tract. B12 together with vitamin A and vitamin B1 is necessary for reproduction, due to the production of DNA. In the synthesis of DNA (the hereditary basic nucleic acids that control the life process of all tissue cells), B12 works in conjunction with folic acid. In building the unit that forms the DNA, it works indirectly in the synthesis of folacin coenzymes. Any rapidly dividing cell of the body needs a continuous supply of B12.

B12 plays an important role in body coenzymes. Coenzymes B12 and coenzymes methyl B12, function in a large variety of reactions in the body chemistry. The functions are countless. We will try to bring to prominence the following functions, which we believe are vital to the metabolism in the human body. It maintains intact the myelin sheath around the nerve structures.

Without B12, folacin cannot be absorbed, and it becomes trapped inside the intestinal wall. This is the reason why a deficiency of B12 produces the same symptoms as a folacin deficiency. B12 is indispensable in the process of releasing folacin from the body storage and to get it into the cells. Without it, folacin is of little use to the human body.

B12 helps iron function and assists with the synthesis of choline. B12 is required to maintain normal growth in children. The mucosa cells from the entire gastrointestinal tract, from the mouth to rectum, cannot replicate without B12. This fact explains diarrhoea that occurs with the b12 deficiency.

It turns food into mental energy and maintains and repairs brain tissue. It keeps the metabolism of carbohydrates, fats and proteins, intact and functioning. B12 in injection has been effective in mild to moderate asthma in children. Many practitioners of alternative medicine describe having good results in treating chronic fatigue syndrome with B12. It maintains and supports the health of every

What Are the Causes of Deficiency

  • Malabsorption is the major cause of the deficiency. The absorption of B12 in the intestines is unique. First, acid from the stomach is required to dissolve and release B12 from foods. The “free” B12 then binds the intrinsic factor in the stomach to form a complex that is absorbed by the intestines. Insufficient acid or intrinsic factor could hinder the absorption of B12 in the intestines, resulting in a deficiency.
  • Atrophic gastritis. About 10-30% of people aged 60 and older are afflicted by atrophic gastritis. Atrophic gastritis is caused by autoimmune disorders, resulting in immune cells wrongly attacking stomach cells. Atrophic gastritis lowers B12 absorption, leading to deficiency. Furthermore, individuals age 60 and older have less acid in the stomach. Insufficient acid affects the release of B12 from ingested foods, reduces the absorption of  B12 in the intestines, and increases the risk of deficiency.

Which Diseases Are Associated with Deficiency

  • Pernicious anaemia. B12 is an essential nutrient for the synthesis of new red blood cells in the bone marrow. The deficiency can cause pernicious anaemia, a condition that cannot be reversed by iron supplementation. Anaemia often is the earliest sign of deficiency. Pernicious anaemia may be due to deficiency or lack of intrinsic factor, which is required for B12 absorption in the intestines. Deficiency of either B12 or intrinsic factor can lead to pernicious anaemia.
  • Nervous system disorders. B12 deficiency triggers numbness in the extremities, memory loss, unconsciousness, and difficulty walking, and in severe cases, it can permanently damage the nervous People who take more than 400 mcg of a vitamin B9 supplement a day should be concerned about the potential hidden problem of deficiency. Vitamin B9 may cure anaemia, but not the underlining problem of deficiency. The deficiency often goes unnoticed until the nervous system is permanently damaged.
  • Digestive system retardation. Stomach surgery or digestive system disorder can cause deficiency. Lack of appetite and constipation are early signs of deficiency as well.

What Are The Food Sources

While vitamin B12 is found naturally in high quantities in many foods, no plant sources provide people with a safe and healthy dose of this important vitamin, which is why B12 supplementation is especially important for vegetarians. See the table below for the list of B12 rich food:

recommended daily intake (RDI) of vitamin B12


How to Take It

The recommended daily intake (RDI) of B12 increases with age. It is highest among pregnant and nursing women. B12 is a part of the B-complex vitamin group (a term given to a group of eight important B vitamins), and most general-purpose multivitamin/mineral supplements contain the full range of B vitamins (be sure to check the label).

Vitamin B12 supplementation is recommended for strict vegetarians (vegans, who do not eat meat, fish, eggs, milk, or milk products), elderly people with reduced absorption of this vitamin, and people who have had stomach surgery or other digestive conditions that can cause a deficiency. Supplementation is also recommended for people who take certain medications that may interfere with the absorption of B12 or reduce its blood levels.

B12 supplements are available in three forms—cyanocobalamin, hydroxocobalamin, and methylcobalamin. Although the first is the most widely available and least expensive of the three, the latter two forms may be more effective. It can be beneficial to take B12 with other B vitamins since they usually work most effectively when taken together.

What to Avoid

Medication: Medicines that reduce acid in the stomach, and colchicine, metformin and phenformin, zidovudine, and nitrous oxide may reduce the body’s ability to absorb B12. Antibiotics, hormone replacement therapy (HRT), oral contraceptives, histamine blockers, some cholesterol-lowering medication and oral hypoglycemic agents, antiseizure medications, and some HIV medications may deplete levels of B12.

Herbs and Dietary Supplements: Slow-release potassium supplements may reduce the body’s ability to absorb B12.

Bottom Line

Vitamin B12 is a safe supplement, and no adverse health effects have been reported even when too much is taken. High doses may, however, worsen acne. Also, a balanced diet probably provides all the added B vitamins you need. If you frequently feel sluggish even though you eat right and get plenty of sleep, talk to your physician.