Insights of Vitamin B-12

vitb12

What is Vitamin B-12?

Vitamin B12, vitamin B12 or vitamin B-12, is a water-soluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood. It is a nutrient that helps in making DNA, the genetic material in all cells.

While most vitamins can be made by a wide variety of plants and specific animals, no plant or animal has been shown capable of producing B12, and the exclusive source of this vitamin appears to be tiny microorganisms like bacteria, yeasts, molds, and algae.

What are the other names of Vitamin B12?

Names for B12 include: cobrynamide, cobinamide, cobamide, cobalamin, hydroxcobalamin, aquocobalamin, nitrotocobalamin, and cyanocobalamin. Each of these designations contains a form of the word “cobalt,” since cobalt is the mineral found in the center of the vitamin.

How Vitamin B12 gets absorbed in our body?

Absorption of B-12 is dependent upon a second substance, called intrinsic factor, to make its way from the “GI” tract (gastrointestinal tract–the stomach and intestines) into the rest of the body. Without intrinsic factor, which is a unique protein made in the stomach, vitamin B12 cannot gain access to the rest of the body where it is needed.

Two steps are required for the body to absorb vitamin B12 from food:

Step 1: Hydrochloric acid in the stomach separates vitamin B12 from the protein to which vitamin B12 is attached in food.

Step 2: After step 1, vitamin B12 combines with a protein made by the stomach called intrinsic factor and is absorbed by the body.

What is the function of Vitamin B12?

Forming red blood cells

Its major role is in the development of red blood cells. As red blood cells mature, they require information provided by molecules of DNA. (DNA, or deoxyribose nucleic acid, is the substance in the nucleus of our cells which contains genetic information.) Without B12, synthesis of DNA becomes defective, and so does the information needed for red blood cell formation. The cells become oversized and poorly shaped, and begin to function ineffectively, a condition called pernicious anemia. More often than not, pernicious anemia isn’t caused by a lack of B12 itself, but by a lack of intrinsic factor — the stomach-made protein required for the absorption of B12.

Developing nerve cells

A second major function of B12, less clearly understood than the first, involves its participation in the development of nerve cells. A coating which encloses the nerves — called the myelin sheath — forms less successfully whenever B12 is deficient. Although the vitamin plays an indirect role in this process, supplementation of B12 has been shown to be effective in relieving pain and other symptoms in a variety of nervous system disorders.

Other roles for vitamin B12

Protein — the component of food required for growth and repair of cells — depends upon B12 for proper cycling through the body. Many of protein’s key components, called amino acids, become unavailable for use in the absence of B12. Since one of the steps in carbohydrate and fat processing requires B12 for its completion, insufficiency of the vitamin can also affect the movement of carbohydrates and fats through the body.

How much vitamin B12 do I need?

The amount of vitamin B12 you need each day depends on your age. Average daily recommended amounts for different ages are listed below in micrograms (mcg):

Life Stage

Recommended Amount

Birth to 6 months

0.4 mcg

Infants 7–12 months

0.5 mcg

Children 1–3 years

0.9 mcg

Children 4–8 years

1.2 mcg

Children 9–13 years

1.8 mcg

Teens 14–18 years

2.4 mcg

Adults

2.4 mcg

Pregnant teens and women

2.6 mcg

Breastfeeding teens and women

2.8 mcg

What are deficiency symptoms for vitamin B12?

Although B12 is not the only nutrient deficiency that can contribute to occurrence of the following symptoms, B12 deficiency should be considered as a possible underlying factor whenever any of the symptoms listed below are present.

Symptoms potentially associated with vitamin B12 deficiency:

  • Dandruff
  • Nervousness
  • Decreased blood clotting
  • Numbness in fingers
  • Decreased reflexes
  • Paleness
  • Depression
  • Red tongue
  • Difficulty swallowing
  • Sore tongue
  • Fatigue
  • Tingling in feet
  • Heart Palpitations (disagreeable sensations of irregular and/or heavy beating of the heart)
  • Weakness
  • Memory problems
  • Weak pulse
  • Menstrual problems
  • Panting (shortness of breath)

What factors might contribute to a deficiency of B12?

B-12 and the stomach

Stomach problems can contribute to a B12 deficiency in two ways.

First, irritation and inflammation of the stomach can prevent the stomach cells from functioning properly. When functioning improperly, the cells may stop producing a substance required for B12 absorption called intrinsic factor (IF). Without IF, B12 cannot be absorbed from the gastrointestinal tract into the body’s cells.

A second way for stomach problems to create B12 deficiency is through inadequate secretion of stomach acids. Lack of stomach acids (a condition called called hypochlorhydria) gets in the way of B12 absorption since most B12 in food is attached to proteins in the food, and stomach acids are necessary to release the B12 from these proteins.

The above stomach problems that can contribute to B12 deficiency have a wide variety of causes. These causes include abuse of over-the-counter antacids, abuse of prescription medicines used to control stomach acidity, and stomach ulcers (also called gastric ulcers), which may themselves be due to infection with the bacteria, helicobacter pylori.

B12 and vegetarianism

Plants are unreliable source of B12. For strict vegetarians who eat no animal products whatsoever, this unreliability may pose a problem. Since no plant is capable of making B-12, the amount of B12 in plant food depends upon the relationship of the plant to soil and root-level microorganisms (bacteria, yeasts, molds, and fungi) which make the vitamin. Cultured and fermented bean products like tofu, tempeh, miso, tamari and shoyu may or may not contain significant amounts of B12, depending upon the bacteria, molds, and fungi used to produce them. The B12 content of sea vegetables also varies according to the distribution of microorganisms in the surrounding sea environment.

Unfortunately, reliable nutrient analyses are often unavailable for consumers of these products, and labeling for B12 content is not required. In general, tofus, tempehs, and sea vegetables tend to be more consistent sources of B12 than misos, tamaris, and shoyus. Depending upon the medium in which they are grown, brewer’s and nutritional yeast can also be significant sources of B12 in a strict vegetarian diet.

What foods provide vitamin B12?

Vitamin B12 is found naturally in a wide variety of animal foods and is added to some fortified foods. Plant foods have no vitamin B12 unless they are fortified. You can get 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.
  • Some breakfast cereals, nutritional yeasts and other food products that are fortified with vitamin B12. To find out if vitamin B12 has been added to a food product, check the product labels.

What kinds of vitamin B12 dietary supplements are available?

Vitamin B12 is found in almost all multivitamins. Dietary supplements that contain only vitamin B12, or vitamin B12 with nutrients such as folic acid and other B vitamins, are also available. Check the Supplement Facts label to determine the amount of vitamin B12 provided.

Vitamin B12 is also available in sublingual forms (which are dissolved under the tongue). There is no evidence that sublingual forms are better absorbed than pills that are swallowed.

A prescription form of vitamin B12 can be administered as a shot. This is usually used to treat vitamin B12 deficiency. Vitamin B12 is also available as a prescription medication in nasal gel form (for use in the nose).

Am I getting enough vitamin B12?

Most people in the United States get enough vitamin B12 from the foods they eat. But some people have trouble absorbing vitamin B12 from food. As a result, vitamin B12 deficiency affects between 1.5% and 15% of the public. Your doctor can test your vitamin B12 level to see if you have a deficiency.

Certain groups may not get enough vitamin B12 or have trouble absorbing it:

  • Many older adults, who do not have enough hydrochloric acid in their stomach to absorb the vitamin B12 naturally present in food. People over 50 should get most of their vitamin B12 from fortified foods or dietary supplements because, in most cases, their bodies can absorb vitamin B12 from these sources.
  • People with pernicious anemia whose bodies do not make the intrinsic factor needed to absorb vitamin B12. Doctors usually treat pernicious anemia with vitamin B12 shots, although very high oral doses of vitamin B12 might also be effective.
  • People who have had gastrointestinal surgery, such as weight loss surgery, or who have digestive disorders, such as celiac disease or Crohn’s disease. These conditions can decrease the amount of vitamin B12 that the body can absorb.
  • Some people who eat little or no animal foods such as vegetarians and vegans. Only animal foods have vitamin B12 naturally. When pregnant women and women who breastfeed their babies are strict vegetarians or vegans, their babies might also not get enough vitamin B12.

How do other nutrients interact with vitamin B12?

Vitamin B6 is required for proper absorption of vitamin B12, and deficiency of vitamin B6 has been shown to impair B12 absorption in animal studies.

Conversion of vitamin B12 from its non-active into its biologically active form requires the presence of vitamin E. Individuals at risk for vitamin E deficiency may show signs of vitamin B12 deficiency as well.

Contrary to research from the mid 1970s, supplemental doses of vitamin C above the 500 milligram level do not appear to compromise B12 function.

Excessive intake of folic acid can mask B-12 deficiencies, and individuals at risk for vitamin B12 deficiency who are also taking folic acid in supplement form should consult with their healthcare practitioner.

What are some effects of vitamin B12 on health?

Scientists are studying vitamin B12 to understand how it affects health. Here are several examples of what this research has shown:

Heart disease
Vitamin B12 supplements (along with folic acid and vitamin B6) do not reduce the risk of getting heart disease. Scientists had thought that these vitamins might be helpful because they reduce blood levels of homocysteine, a compound linked to an increased risk of having a heart attack or stroke.

Dementia
As they get older, some people develop dementia. These people often have high levels of homocysteine in the blood. Vitamin B12 (with folic acid and vitamin B6) can lower homocysteine levels, but scientists don’t know yet whether these vitamins actually help prevent or treat dementia.

Energy and athletic performance
Advertisements often promote vitamin B12 supplements as a way to increase energy or endurance. Except in people with a vitamin B12 deficiency, no evidence shows that vitamin B12 supplements increase energy or improve athletic performance.

Can vitamin B12 be harmful?

Vitamin B12 has not been shown to cause any harm.

How is B12 deficiency diagnosed?

A GP (general practitioner, primary care physician) will interview the patient and carry out a physical examination, looking out for such signs as an accelerated pulse and pale/yellowish skin.

  • Blood test – to determine whether the red blood cell count is low. The appearance of the red blood cells is also checked, because they may have an unusual shape. A blood test can also determine what the level of B12 is.The GP may also want to check the patient’s blood intrinsic factor antibody levels, in order to determine whether the person has pernicious anemia.
  • Bone marrow biopsy – the aim here is to rule out other possible causes of red cell abnormalities or anemia.

Vitamin B12 is essential to the very foundation of life itself – it’s one of the building blocks your body uses to produce DNA. It also keeps your immune system functioning optimally, regulates mood and sleep cycles,and is crucial to energy production, which is why it’s known as the “energy vitamin. It also protects your brain and nervous system by keeping nerves healthy and communicating in an optimal manner. And emerging research is showing that B12 helps to lower levels of the stress marker homocysteine, making it a vital player in maintaining heart and brain health.

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