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Chapters

0:00 Introduction
1:00 Benefits and signs of deficiency
1:04 Benefits of vitamin B6
1:32 Signs of B6 deficiency
2:13 Benefits of vitamin B9(folate or folic acid)
2:34 Signs of vitaminB9 deficiency
2:49 Benefits of vitamin B12
3:12 Signs of vitamin B12 deficiency
3:34 Causes of Vitamin B Deficiency


Vitamin B12 deficiency, also known as cobalamin deficiency, is the medical condition in which the blood and tissue have a lower than normal level of vitamin B12.[5] Symptoms can vary from none to severe.[1] Mild deficiency may have few or absent symptoms.[1] In moderate deficiency, feeling tired, anemia, soreness of the tongue, mouth ulcers, breathlessness, feeling faint, rapid heartbeat, low blood pressure, pallor, hair loss, decreased ability to think and severe joint pain and the beginning of neurological symptoms, including abnormal sensations such as pins and needles, numbness and tinnitus may occur.[1] Severe deficiency may include symptoms of reduced heart function as well as more severe neurological symptoms, including changes in reflexes, poor muscle function, memory problems, blurred vision, irritability, ataxia, decreased taste and smell, decreased level of consciousness, depression, anxiety, guilt and psychosis.[1] If left untreated, some of these changes can become permanent.[1][6] Temporary infertility reversible with treatment, may occur.[1][7] In exclusively breastfed infants of vegan mothers, undetected and untreated deficiency can lead to poor growth, poor development, and difficulties with movement.[2]

Causes are usually related to conditions that give rise to malabsorption of vitamin B12 particularly autoimmune gastritis in pernicious anemia.[8] Other conditions giving rise to malabsorption include surgical removal of the stomach, chronic inflammation of the pancreas, intestinal parasites, certain medications such as long-term use of proton pump inhibitors, H2-receptor blockers, and metformin, and some genetic disorders.[1][9] Deficiency can also be caused by inadequate dietary intake such as with the diets of vegetarians, and vegans, and in the malnourished.[1][10] Deficiency may be caused by increased needs of the body for example in those with HIV/AIDS, and shortened red blood cell lifespan.[1] Diagnosis is typically based on blood levels of vitamin B12 below 150–180 pmol/L (200 to 250 pg/mL) in adults.[2] A false high or normal assay may be observed.[11] Elevated methylmalonic acid levels may also indicate a deficiency.[2] A type of anemia known as megaloblastic anemia is often but not always present.[2] Individuals with low or marginal values of vitamin B12 in the range of 148–221 pmol/L (200–300 pg/mL) may not have classic neurological or hematological signs or symptoms.[2]

Treatment is by vitamin B12 supplementation, either by mouth or by injection.[3] Initially in high daily doses, followed by less frequent lower doses, as the condition improves.[3] If a reversible cause is found, that cause should be corrected if possible.[12] If no reversible cause is found, or when found it cannot be eliminated, lifelong vitamin B12 administration is usually recommended.[13] A nasal spray is also available.[2] Vitamin B12 deficiency is preventable with supplements, which are recommended for pregnant vegetarians and vegans, and not harmful in others.[2] Risk of toxicity due to vitamin B12 is low.[2]

Vitamin B12 deficiency in the US and the UK is estimated to occur in about 6 percent of those under the age of 60, and 20 percent of those over the age of 60.[4] In Latin America, about 40 percent are estimated to be affected, and this may be as high as 80 percent in parts of Africa and Asia.[1] Marginal deficiency is much more common and may occur in up to 40% of Western populations.[2]

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