Vitamin B12 Supplementation

Lactic acidosis (buildup of lactic acid in the blood) may also occur with die administration of metformin. Although lactic acidosis is a rare adverse reaction, its occurrence is serious and can be fatal. Lactic acidosis occurs mainly in patients with kidney dysfunction. Symptoms of lactic acidosis include malaise (vague feeling of bodily discomfort), abdominal pain, rapid respirations, shortness of breath, and muscular pain. In some patients vitamin B12 levels are decreased. This can be reversed with vitamin B12 supplements or with discontinuation of the drug therapy. Because... 

Oral vitamin B12 supplementation appears to be as effective as parenteral, even in patients with pernicious anemia, because the alternate vitamin B12 absorption pathway is independent of intrinsic factor. Oral cobalamin is initiated at 1 to 2 mg daily for 1 to 2 weeks, followed by 1 mg daily. 

Among the aged, deficiency of vitamin B12 is rather common. Upon aging, many people become unable to absorb adequate amounts of vitamin B12 from the diet. Functional deficits are the result. These are easily overcome by the monthly injection of vitamin B12 supplements. 

Vitamin B12 supplement Cyanocobalamin Nascobal Methylcellulose Aqueous... 

Oakley GP Jr (2004) Oral synthetic folic acid and vitamin B12 supplements work — if one consumes them. Nutr Rev, 62(6 Pt 2) S22-S26 discussion S27-S28. 

Yeast and algae Yeast and Se supplement Vitamin B12 supplement Meat and offal Beef Chicken Chicken Chicken Pig kidney Porcine liver... 

Table 17.6 Haemoglobin levels (g/l) in a group of vegans before and after vitamin B12 supplementation...

As an example, we will consider (Table 17.6) some changes that occurred in haemoglobin levels in a group of vegans when given vitamin B12 supplementation. The study was paired, each individual providing a pre-treatment blood sample and then a further sample after 4 weeks of supplementation. 

Vitamin B12, cobalamin or cyanocobaltamin, C63H88CoN14Oi4P, has the most complicated structure of the B vitamins. It contains one atom of cobalt in its molecule. It is required in minute amounts but without it the manufacture of proteins and red blood cells is affected. A diet which is deficient in liver, eggs, meat, fish or milk can lead to pernicious anaemia. Vegetarians are often advised to take vitamin B12 supplements. 

Myelosuppression increased in patients with elevated cystathioneine or homocysteine concentrations. Folic acid and vitamin B12 supplementation decrease myelosuppression by decreasing elevated cystathionine and homocysteine levels. 

Vitamin B12 is made naturally by bacteria that live in the intestines of all animals, including humans, as well as in soil. It binds to protein in food. Plants do not synthesize vitamin B12. Manufacturers who make vitamin B12 supplements use bacteria to grow the vitamin by a process similar to that which occurs naturally. Good food sources of vitamin B12 include animal foods, such as fish, meat, poultry, eggs, milk, cheese, and yogurt as well as fortified cereals. People who do not eat animal products should be sure to select foods fortified with artificially produced vitamin B12, because the synthetic vitamin is produced by a natural process that does not involve the destruction of animals or the consumption of animal products. 

Bea Twelvlow was diagnosed with an inability to absorb dietary B12 but j not crystalline B12 (the Schilling test results were normal). One of the con- sequences of aging is a reduced acid production by the gastric mucosa (atrophic gastritis), which limits the ability of pepsin to work on dietary protein. A reduced pepsin efficiency would then reduce the amount of bound B12 released from dietary protein, as a result of which the B12 would be unavailable for absorption. Because Bea absorbs crystalline B12 without a problem, her condition can be easily treated by taking vitamin B12 supplements orally. 

Vitamin B12 and a number of biologically inactive vitamin B12 analogues are synthesised by microorganisms in the rumen and, in spite of poor absorption of the vitamin from the intestine, the ruminant normally obtains an adequate amount of the vitamin from this source. However, if levels of cobalt in the diet are low, a deficiency of the vitamin can arise and cause reduced appetite, emaciation and anaemia (see p. 125). If cobalt levels are adequate, then except with very yoimg ruminant animals, a dietary source of the vitamin is not essential. Horses also are supplied with sufficient B12 from microbial fermentation when sufficient cobalt is supplied. Parasitised horses have responded to vitamin B12 supplementation, presmnably as a result of impaired digestive activity. 

Vitamin B12 supplementation shows improvement in some eognitive functions (e.g. language function), but rarely reverses dementia. 

At present, the treatment of neuropsychiatric disorders by vitamin B12 supplementation is based mainly on hematological studies. 

Remission of hematological symptoms (megaloblastosis) can occur within few weeks of parentral vitamin B12 supplementation in small doses. Treatment of patients with vitamin B12 deficiency with folic acid leads to aggravation of neurological complications. 

The Vitamin Intervention for Stroke Prevention (VISP) study is a double-masked, randomised, multicentre elinical trial designed to determine if, in addition to best medical/surgieal management, high-dose folic add, vitamin Bg and vitamin B12 supplements will reduee reeurrent stroke compared to lower doses of these vitamins. 

Since B12 only occurs in meat, deficiendes are likely to result firom a strict vegetarian diet containing no animal produrts. Vitamin B12 defidency is also estimated to affect 10-15% of individuals over the age of 60. Vitamin B12 is absorbed firom the small intestine as a complex with a protein called intrinsic factor (IF). The most common cause of vitamin B12 defidency is pernicious anaemia which is an autoimmune disease where the cells of the stomach become inflamed and do not secrete the required amounts of add and enzymes to release vitamin B12 firom food. In addition, antibodies to IF further prevent B12 absorption. The condition is treated with high doses of vitamin B12 supplements or by intramuscular injection of vitamin B12. A similar condition occurs in the elderly where there is malabsorption of vitamin B12 horn food due to decreased secretion of stomach add. This condition is easier to treat with supplementation since IF levds are still normal. Symptoms indude megaloblastic anaemia, neuropathy, memory loss and abnormalities of lipid metabolism. 

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