Vitamin B12 is a water-soluble vitamin that plays important roles in energy production, DNA synthesis, and neurological function. It is found naturally in animal products like meat, fish, dairy, and eggs. Vitamin B12 deficiency can cause anemia and damage to the nervous system. It is usually caused by lack of absorption rather than intake. Treatment involves B12 injections or supplements.

1. Vitamin B12

2. Vitamin B12
 It is a Vitamin from B group, and it is soluble in water.
 It has been discovered through attempts to treat anemia.
 In 1948, the scientists isolated a red compound from the liver, and
give it a number B12.
 The Scientists called this red compound a Cobalamin, because it
has a Cobalamin atom in the middle.

3. Vitamin B12
 Vitamin B12 and Folic acid depend on each other, because VitB12
works by removing a methyl group to activate enzyme of folate
cofactor.
 On the other hand, Folic acid gives a methyl group to the VitB12 to
activate the enzyme cofactor of VitB12.

4. Complex Structure of Vitamin B12

5. Daily Requirements of Vitamin B12
Age Group Daily Requirements (Microgram/day)
Infants 0-6 months 0.4
Infants 7-12 months 0.5
Children 1-3 years 0.9
Children 4-8 years 1.2
Children 9-13 years 1.8
Teenager 14-17 years 2
Adults 18 and more 2.4
Pregnant Women 2.6
Breastfeeding Women 2.8

6. Functions of Vitamin B12
 It has a major role in the manufacturing energy through
maintaining healthy body cells.
 It provides the brain cells with the energy necessary to maintain
the proper balance that the body needs to think and move.
 It has a key role in protecting the heart by removing the
homocysteine protein from the blood.
 It helps to prevent osteoporosis also by removing homocysteine
protein from the blood.

7. Functions of Vitamin B12
 It plays an important role in the process of protein synthesis, and
the production of hemoglobin, which gives the blood its red color.
 It plays a key role in the synthesis of proteins and fat in the myelin
sheath that surrounds nerve fibers in the brain and spinal cord, and
thus protects them.
 It Helps improve mood by maintaining adequate concentration of
serotonin in the brain.
 It Helps in the prevention of Alzheimer's disease.
 It delays the onset of aging symptoms by maintaining healthy body
cells.

8. Reasons for Vitamin B12 Deficiency
 Vitamin B12 deficiency is usually due to lack of absorption, and not
due to lack of intake.
 Vitamin B12 deficiency is due to several causes:
1: Deficiency of hydrochloric acid in the stomach, which inhibits the
digestion of proteins that are linked to vitamin.
2: Lack of internal factor that helps absorption of the vitamin.
3: Removal part of the stomach or small intestine surgically.
4: Frequent use of antacids or a lot of alcohol.

9. Symptoms of Vitamin B12 Deficiency
 An Anemia with large macromolecules of large pellets.
 Damage to nerves.
 Decline in intelligence, speed of forgetfulness, and short-term
memory loss.
 Feeling numbness in the limbs and difficulty in walking.
 General fatigue, rapid heartbeat and breathing caused by the lack
of red blood cells in the transfer of oxygen.

10. Symptoms of Vitamin B12 Deficiency
 Gastrointestinal problems such as constipation, diarrhea, and gases
 Yellowing in skin color and eyes.
 Depression.
 Unclear vision or loss of sight.
 Difficulty in Speaking.

11. Treatment of Vitamin B12 Deficiency
 Treatment of vitamin B12 deficiency is one of the easiest
treatments, and there are several ways:
1: Give vitamin B12 injections especially in the cases of pernicious
anemia.
2: B12 supplements are given orally.
3: Nose spray contains vitamin B12.
4: Eating foods containing vitamin B12.

12. Absorption of Vitamin B12
 Vitamin B12 is associated with proteins and must be released from
these proteins by digestion through pepsin enzyme in the stomach
until it absorbed. Then, Vitamin B12 binds to the R proteins in the
stomach and carries them to the small intestine where these
proteins are digested and vitamin B12 is released.
 Then it binds to a special product produced by the stomach called
the internal factor, and they bind to special receptors located on
the cells of the segment of the glomerular at the bottom of the
small intestine, where the absorption of cobalamin occurs, and put
the inner factor away.
 99% of vitamin B12 is absorbed in this way, while 1% is absorbed by
the simple diffusion method.

13. Transfer and Storage of Vitamin B12
 The cobalamin travels in the blood after it binds to the R proteins
present in the plasma, and is received by the cells of the body by
special receptors to perform its role as an coenzyme in its various
functions.
 Vitamin B12 is stored in healthy people who receive healthy liver
nutrition in quantities sufficient for 5-7 years.
 The liver contains 50% of the vitamin B12 stock in the body, while
the remainder is distributed within the cells of the body.

14.  Red Meat.
 Milk.
 Eggs.
 Cheese.
 Fish.
 Poultry.

16. Vitamin B12 and Heart Diseases
 High levels of homocysteine in the blood raise the risk of
cardiovascular diseases and stroke by its role in atherosclerosis,
where vitamin B12 deficiency increases the level of homocysteine
in the blood.
 Researchers observe that vitamin B12 helps to lower the level of
homocysteine, so vitamin B12 deficiency is associated with a higher
risk of cardiovascular diseases.

17. Vitamin B12 and Heart Diseases

18. Vitamin B12 and Osteoporosis
 Studies have shown the role of this vitamin in the formation and
proliferation of bone-building cells, and therefore has an important
role in the prevention of osteoporosis.