Functions Sources and Deficiency Symptoms of Vitamin B12

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Functions Sources and Deficiency Symptoms of Vitamin B12

Vitamin B12 also called as Cobalamin. It is a water soluble vitamin. Vitamin B12 plays a key role in the normal functioning of the brain and nervous system and for the formation of the blood. It is a unique vitamin, synthesized by only microorganisms and not by animals and plants. The two coenzyme forms of vitamin B12 are Methylcobalamin and 5’-Deoxyadenosyl Cobalamin. The vitamin B12 is present in the diet in a bound form to proteins.

What are the Functions of Vitamin B12?

  • Vitamin B12 normally involved in the metabolism of every cell of the human body especially affecting DNA synthesis and regulation , fatty acid metabolism and amino acid metabolism
  • Vitamin B12 acts as a cofactor for methionine synthase and L-methyl malonyl-coenzyme A mutase
  • Vitamin B12 is vital for the formation of red blood cells
  • Vitamin B12 plays important role in the normal functioning of the brain and nervous system
  • Vitamin B12 is necessary for the synthesis of metrhionine from homocysteine

What is the RDA for vitamin B12?

Recommended dietary allowance (RDA):-average daily level of intake sufficient to meet the nutrient requirements of nearly all healthy individuals.

  • 0-6 months                               0.4 mcg
  • 7-12 months                             0.5 mcg
  • 1-3 years                                     0.9 mcg
  • 4-8 years                                     1.2 mcg
  • 9-13 years                                   1.8 mcg
  • 14-18 years                                 2.4 mcg
  • 19+years                                     2.4 mcg
  • Pregnancy                                   2.6 mcg
  • Lactating women                       2.8 mcg

What are the sources of Vitamin B12?

Vitamin B12 is found naturally in a wide variety of animal foods. Foods of animal origin are the only sources for vitamin B12. Curd is a better source than milk, due to the synthesis of B12 by Lactobacillus. Vitamin B12 is synthesized only by micro-organisms. Plant foods have no vitamin B12 unless they are fortified. The best way to meet your body’s vitamin B12 needs is to eat a wide variety of animal products.

  • Organ meats (beef liver)
  • Shellfish
  • Meat, poultry, eggs and milk
  • Fortified soy products
  • Fortified cereals
  • Red meat
  • Swiss cheese

What are the Deficiency Symptoms of Vitamin B12?

The most important disease associated with vitamin B12 deficiency is pernicious anemia. It is characterized by low hemoglobin levels, decreased number of erythrocytes and neurological manifestations.

  • B 12 deficiency anemia:-in B12 deficiency the body produces larger than normal blood cells.
  • Weakness, tiredness or light headedness
  • Rapid heartbeat and breathing
  • Pale skin
  • Easy bruising or bleeding, bleeding gums, mouth ulcers
  • Stomach upset and weight loss
  • Diarrhea and constipation
  • Yellowing of the skin
  • Sore, red tongue
  • Mouth ulcers
  • Mood changes, irritability, depression or psychosis
  • Tinnitus (ringing in the ears)

vitamin b12What are the causes of Vitamin B12 Deficiency?

In healthy adults, vitamin B12 deficiency is uncommon. Deficiency is more common mainly because of impaired intestinal absorption that can result in marginal to severe vitamin B12 deficiency in this population.

  • The most common cause of vitamin B12 deficiency is Pernicious anemia, an autoimmune condition caused by a lack of a protein called intrinsic factor that’s needed to absorb vitamin B12 from food into the body from the gastrointestinal tract.
  • Intestinal malabsorption:-absorption of vitamin B12 from food requires normal function of the stomach, pancreas and small intestine.
  • Atrophic gastritis:-this condition is frequently associated with the presence of autoantibodies directed towards stomach cells. Diminished gastric function in individuals with a atrophic gastritis can result in bacterial over growth in the small intestine and cause food bound B12 malabsorption
  • Vitamin B12 levels in serum, plasma and gastric fluids are significantly decreased in individuals with Hpylori infection
  • Surgical resection of the stomach or portion of the small intestine where receptors for the IF-B12 complex are located
  • Chronic alcoholism:- reduced in absorption of vitamin B12
  • Digestive conditions such as Crohn’s disease, Coeliac disease
  • Medication including proton pump inhibitors for indigestion

What is the Treatment for Vitamin B12 Deficiency?

Vitamin B12 deficiency treatment depends on the cause. If pernicious anemia or a problem with absorption is the cause, you will need to replace B12 usually by injection or by prescription. For most people treatment resolves the problem. But any nerve damage that happened due to the deficiency could be permanent. A combined therapy of vitamin B12 and folic acid is generally employed to treat the patients with megaloblastic anemia.

How to Prevent Vitamin B12 Deficiency?

  • Vitamin B12 deficiency can be prevent by eating enough meat, sea food, dairy products and eggs
  • Vegetarians can get vitamin B12 by taking cereal fortified with vitamin B12
  • Consult your doctor for the B12 supplements.
  • For people who cannot absorb B12, the condition cannot be presented. However, once it is diagnosed, regular injection of vitamin B12 will prevent symptoms from returning