Vitamin B12 It is necessary for the creation of red blood cells. The functioning of the nervous system, both central and peripheral. Plays an important role in the process of burning fat and protein at the cellular level. (Methionine cycle) waste disposal Synthesis of DNA, RNA, proteins, and hormones.  

Vitamin B12 In natural foods, it is usually bound to animal protein. When ingested, sufficient amounts of Hydrochloric acid and gastric protein must be used. To separate vitamin B12 before it can be absorbed into the body.

But from the Framingham Offspring Study published in 2000, it was found that at present, younger people (26-49 years) experience vitamin B12 deficiency at a rate that is no different from the elderly group. ^[1]

Symptoms of vitamin B12 deficiency

Symptoms of people with vitamin B12 deficiency are quite diverse (highly polymorphic) in terms of severity. And joint abnormalities can be found in many systems and organs. It may be found from slight numbness in the nerve endings. or found abnormalities in red blood cells without any symptoms at all Some people may come with symptoms of being easily tired, fatigued, depressed, depressed, or even very severe symptoms such as ataxia, sclerosis of the spinal cord, hemolytic anemia, or bone marrow not producing blood cells. (pancytopenia) ^[2]

Risk of anemia

Anemia caused by a lack of vitamin B12 (Pernicious Anemia) is a disease. Autoimmune where the destruction occurred Stomach cells (parietal cells) cause decreased acid secretion. Less absorption of vitamin B12 (Malabsorption) is not sufficient for the production of red blood cells. In addition to chronic fatigue from a lack of oxygen at the cellular level, There may also be neurological symptoms. Such as hearing strange sounds in the ears (Tinnitus). ^[3]

Numbness of the hands and feet

deficiency Vitamin B12 It can cause a variety of neurological symptoms. Both hands and feet are numb. From peripheral neuropathy, pain in the fifth facial nerve (trigeminal neuralgia), or even strange nerve ending pain in the face in a variety of locations and symptoms (isolated facial neuralgia), including dull pain and localized pain. (sharp shooting) and pain from constantly changing places (Fleeting) ^[4]

Nervous system and brain

lack Vitamin B12 Affects thinking, memory, perception and brain performance (Cognitive functions) and is also associated with degenerative diseases of the nervous system. (Neurodegenerative diseases) such as dementia and Alzheimer's, which are also associated with higher Homocysteine levels. ^[5] Supplementing vitamin B12 in people who are deficient can help. Improve Cognition of the patient ^[6]

Risk of heart disease and stroke

level Homocysteine Higher levels are also an important factor (Independent Risk Factor) of cardiovascular disease. ^[7] This is a disease that has the highest death rate today. Although various prevention trials (Prevention Trials) have different conclusions in terms of Vitamin B supplementation to prevent major cardiovascular events and reduce total mortality, but the American Heart Association concluded that there is sufficient evidence to support the use of vitamin B. (The American Heart Association has concluded that the available evidence is adequate to support a role for B vitamins in reducing cardiovascular risk.) ^[7]

Check vitamin B12 deficiency levels

Assessment of vitamin B12 deficiency by measuring vitamin B12 levels directly from the blood (Serum B12 Level) was found to be not accurate. and does not reflect the level of vitamin B12 at the cellular level (Intracellular B12 Concentrations). Homocysteine level testing. It may help to provide more information. But it's still not very specific. to vitamin B12 deficiency alone (Poor Specificity) testing of organic acid levels Methylmalonic acid is considered an accurate indicator. and most reliable ^[8,9] Because it reflects the actual functioning at the cellular level (Functional indicator of tissue level deficiency)

Summary of 4 main symptoms of people who lack vitamin B12

• Fatigue of unknown cause (malaise and fatigue) easily tired, weak body muscle weakness, anemia
• depressed depressed (depression) has problems with learning, decision making, and memory loss (dementia)
• Numbness of the tips of the hands and feet Pain in the nerves in the face (facial neuralgia). Problems with balance.
• Pale, yellow skin and tongue Sore tongue, inflammation of the tongue (glossitis), sores in the mouth, or blisters on the lips (cold sores)

Summary of 5 groups at risk for vitamin B12 deficiency.  

• People with chronic gastrointestinal symptoms (chronic dyspepsia) which affect the absorption of vitamins and nutrients.
• Elderly people over 50 years have been found to have a decreased absorption of vitamin B12 along with eating less food. and avoid meat
• People who regularly take antacids Makes less acid come out This prevents vitamin B12 from being broken down from food.
• People who have been strictly vegetarian for 2 years or more need a vitamin B12 supplement.
• Diabetic patients who take Metformin for a long time should be examined and compensate for vitamin B12

References:
[1] Plasma vitamin B12 concentrations related to intake source in the Framingham Offspring Study, The American Journal of Clinical Nutrition (2000)
[2] B12 Deficiency: A Look Beyond Pernicious Anemia, The Journal of Family Practice (2007)
[3] Tinnitus as a presenting symptom in Pernicious Anemia, Ann Otol Rhinol Laryngol (1979)
[4] Facial Neuralgia may be link to vitamin B12 deficiency, Neurology Review (2009)
[5] B-Vitamins and Prevention of Dementia, The Proceedings of The Nutrition Society (2008)
[6] Cognitive impairment and Vitamin B12, International Psychogeriatrics (2012)
[7] Diet and lifestyle recommendations revision 2006: a scientific statement from the American Heart Association Nutrition Committee. Circulation (2006)
[8] Cobalamin and Folate Evaluation: Measurement of Methylmalonic acid and Homocysteine VS Vitamin B12 and Folate, Clinical Chemistry (2000)
[9] Measurement of Methylmalonic acid, Homocysteine and Methionine in Cobalamin and Folate deficiencies and Homocysteinurea, Tidsskr Nor Laegeforen (2008)