|
B vitamins |
Main functions |
Sources |
Daily dosage |
|
B1 (Thiamine) |
Converts food (mainly carbohydrates) into energy |
Whole grains |
1-2 mg |
|
B2 (Riboflavin) |
Promotes healthy skin, hair and nails |
Whole grains Yeast extract |
1-1.6 mg |
|
B3 (Niacin) |
Nervous system health Production of sex hormones |
Whole grains Lean meat |
16-18 mg |
|
B5 (Pantothenic acid) |
Boosts immune system Improves energy level |
Brewer’s yeast Liver, kidney |
5-10 mg |
|
B6 (Pyridoxine) |
Healthy immune system Regulates sex hormones |
Wheat germ, Bananas, fish |
1.3-2.0 mg |
|
B12 (Cobalamin) |
Nervous system health Overall growth |
Liver, beef, Fish, eggs |
2.4-2.8 mcg |
|
Bioton (Vitamin H /Co-enzyme R) |
Converts food into energy Health of skin and hair |
Peanuts, almonds, Kidney, egg yolk |
30-35 mcg |
|
Folic acid |
Prevents anemia and birth defects |
Wheat germ, liver, Black-eyed beans |
400-600 mcg |
|
Choline and Inositol |
Lowers cholesterol level Improves memory and concentration |
Liver, egg yolk, Brewer’s yeast, Peanuts |
425-550 mg 500 mg-4 gm |
(For more detailed information, please view the “Search” page.)
General Abstracts
· A daily supplement of B vitamins (folic acid, vitamin B6 and B12) may reduce the risk of breast cancer and other invasive cancers in women over the age of 65; however, in younger women no protective or harmful effects were observed.
o
Source: Journal of the
American Medical Association
November 4, 2008, Volume 300, Issue 17, Pages 2012-2021
" Effect of Combined Folic Acid, Vitamin B6, and Vitamin B12 on Cancer Risk
in Women"
Authors: S. M. Zhang, N.R. Cook, C.M. Albert, J.M. Gaziano, J.E. Buring, J.E.
Manson.
Summary
Folic acid is necessary for DNA replication and repair, the maintenance of the integrity of the genome, and the regulation of gene expression. In the intestinal wall, folic acid is converted to the naturally circulating form of folate. Deficiency may cause megaloblastic anemia, as well as increased risk of cardiovascular disease, certain types of cancer, and Alzheimer’s disease. Rich sources are liver, oranges, and dark green leafy vegetables. Recommended daily allowance is 400 micrograms/day. (For more detailed information, please visit ISM’s searchable database: Nutraceutical Search.)
· Alcohol increases breast cancer risk. However, this increased risk is only observed if folic acid intake is less than 300mcg of folic acid per day.
o European Journal of Clinical Nutrition 2006;60:280-6
· High intake of folate or adequate circulating levels of folate may reduce the risk of breast cancer.
o Curr Opin Obstet Gynecol. 2004 Feb; 16(1): 19-25.
· Higher dietary folate intake is associated with a reduced risk of breast cancer. The risk may even be further reduced in women who also consume high amounts of dietary vitamin B12.
o Shrubsole, Cancer Res (2001);61:7136-41
· Women with deficiency of Folate are 5x more likely to develop precancerous cells.
o Butterworth, JAMA (1992) 267(4):528-33
· Folate from dietary sources alone was related to a modest reduction in risk for colon cancer, and the benefit of long-term multivitamin use was present across all levels of dietary intakes. Long-term use of multivitamins may substantially reduce risk for colon cancer. This effect may be related to the folic acid contained in multivitamins.
o Annals of Internal Medicine. 1998 October; 129(7): 517-524.
· Folate is essential for regenerating methionine, the methyl donor for DNA methylation, and for producing the purines and pyrimidines required for DNA synthesis. Inadequate availability of folate may contribute to aberrations in DNA methylation and may lead to abnormalities in DNA synthesis or repair, either of which may influence colon carcinogenesis.
o Annals of Internal Medicine. 1998 October; 129(7): 517-524.
· Genetic instability, including chromosomal imbalance, is important in the pathogenesis of lymphoproliferative disorders such as non-Hodgkin lymphoma (NHL). DNA synthesis and methylation, which are closely linked to folate metabolism and transport, may be affected by polymorphisms in genes involved in these pathways. Folate metabolism polymorphisms have been linked to acute lymphoblastic leukemia and colorectal cancer. Further investigations are warranted in larger series with dietary information to determine the roles that genetics and folic acid status play in the etiology of lymphoma.
o Cancer Epidemiol Biomarkers Prev. 2005 Dec;14(12):2999-3003.
· The vitamins folic acid, B12 and B6 and B2 are the source of coenzymes that participate in one carbon metabolism. In this metabolism, a carbon unit from serine or glycine is transferred to tetrahydrofolate (THF) to form methylene-THF. This is either used as such for the synthesis of thymidine, which is incorporated into DNA, oxidized to formyl-THF which is used for the synthesis of purines, which are building blocks of RNA and DNA, or it is reduced to methyl-THF which used to methylate homocysteine to form methionine, a reaction which is catalyzed by a B12-containing methyltransferase. Much of the methionine which is formed is converted to S-adenosylmethionine (SAM), a universal donor of methyl groups, including DNA, RNA, hormones, neurotransmitters, membrane lipids, proteins and others. Because of these functions, interest in recent years has been growing particularly in the area of aging and the possibility that certain diseases that afflict the aging population, loss of cognitive function, Alzheimer's disease, cardiovascular disease, cancer and others, may be in part explained by inadequate intake or inadequate status of these vitamins. For (colorectal) cancer DNA hypomethylation is thought to be the link between the observed relationship between inadequate folate status and cancer. We need more studies to confirm that these vitamins have important functions in the etiology of these diseases. We also need to establish if these diseases can be prevented or diminished by proper nutrition starting at a younger age.
o J Nutr Health Aging. 2002;6(1):39-42
· Increased intakes of folate from the diet may reduce a woman’s risk of colorectal cancer by about 50 per cent. when the researchers focussed on the sex of the participants, only women were found to benefit, with the highest levels of folate intake were linked to a 64, 66, and 70 per cent reduced risk of colorectal, colon, and rectal cancer, respectively.
o Source: European Journal of Clinical Nutrition
o Published online ahead of print, doi:10.1038/ejcn.2009.37
o “Folate intake and the risk of colorectal cancer in a Korean population”
o
Authors: J. Kim, D.H. Kim, B.H.
Lee, S.H. Kang, H.J. Lee, S.Y. Lim, Y.K. Sun, Y.O. Ahn
Summary
Vitamin B-3 has antihyperlipidemic activity and lowers serum levels of total cholesterol. It has been found to significantly decrease cardiovascular and cerebrovascular events in high doses. Deficiency may cause pellagra. Rich sources are red meat, poultry, fish, yeast, and legumes. Recommended daily allowance is 20 milligrams/day. (For more detailed information, please visit ISM’s searchable database: Nutraceutical Search.)
Abstracts
· The dietary status of niacin (vitamin B3) has the potential to influence DNA repair, genomic stability, and the immune system, eventually having an impact on cancer risk, as well as the side effects of chemotherapy in the cancer patient.
o Nutr Cancer. 2003; 46(2): 110-8.
· Carcinoid cancer patients often have elevated levels of serotonin or its precursor 5-hydroxytryptophan. Normally, serotonin synthesis accounts for a small fraction of tryptophan catabolism, which should be directed along a pathway that allows partial conversion to niacin; hence, increased diversion of tryptophan toward serotonin could cause variable degrees of niacin deficiency in carcinoid patients. Biochemical niacin deficiency is more prevalent among newly diagnosed CCS patients than in controls.
o Am J Gastroenterol. 2005 Oct;100(10):2307-14.
· Niacin makes radiation therapy more effective at killing hypoxic (low O2) cancer cells.
o Kjellen, Radiotherapy Oncology, (1991) vol 22, p 81
· Niacin in 106 bladder cancer patients receiving surgery & radiation provided substantial improvement in survival (72% vs. 27%) over a control group.
o Popov, Med. Radiol. Mosk. (1987) vol 32, p.42
Summary
Vitamin B-6 is involved in a wide range of biochemical reactions, including the metabolism of amino acids and glycogen, the synthesis of nucleic acids, hemogloblin, and the synthesis of the neurotransmitters serotonin, dopamine, norepinephrine, and gamma-aminobutyric acid (GABA). Deficiency may cause anemia, seizures, inflammation in the mouth, and dermatitis. Rich sources are meat, starchy vegetables, non-citrus fruits, and fortified foods. Recommended daily allowance is 2 milligrams/day. (For more detailed information, please visit ISM’s searchable database: Nutraceutical Search.)
Abstracts
· B-6 supplements through 8 weeks of radiation in endometrial cancer patients provided a 15% survival increase at 5 years.
o Ladner, Nutrition, Growth & Cancer, (1988) p 273
· Increased intake of vitamin B6 from dietary and supplements may reduce the risk of colorectal cancer by over 20 per cent.
o
Source: Cancer Epidemiology
Biomarkers & Prevention
1st January 2008, Volume 17, Pages 171-182, doi:
10.1158/1055-9965.EPI-07-0621
"Dietary Vitamin B6 Intake and the Risk of Colorectal Cancer"
Authors: E. Theodoratou, S.M. Farrington, A. Tenesa, G. McNeill, R.
Cetnarskyj, R.A. Barnetson, M.E. Porteous, M.G. Dunlop, H. Campbell
· Increased intake of vitamin B6 from dietary and supplements may reduce the risk of colorectal cancer by over 50 per cent (Harvard study).
o
Source: Cancer Epidemiology,
Biomarkers & Prevention
2009, Volume 18, Pages 1197-1202 doi: 10.1158/1055-9965.EPI-08-1001
“Prospective Study of Plasma Vitamin B6 and Risk of Colorectal Cancer in Men”
Authors: J.E. Lee, H. Li, E. Giovannucci, I.-M. Lee, J. Selhub, M. Stampfer, J.
Ma
· Low intake of vitamin B6 may increase a man's risk of colorectal cancer by 31 per cent. Men with higher alcohol intake also benefited from the potentially protective effects of vitamin B6.
o
Source: Journal of Nutrition
July 2007, Volume 137, Pages 1808-1814
"Low Intake of Vitamin B-6 Is Associated with Increased Risk of Colorectal
Cancer in Japanese Men"
Authors: J. Ishihara, T. Otani, M. Inoue, M. Iwasaki, S. Sasazuki, S.
Tsugane and for the Japan Public Health Center-based Prospective Study Group
· B-6 decreases the risk of lung cancer. Epidemiological research suggests that male smokers with higher serum levels of pyridoxine have a lower risk of lung cancer.
o Curhan, J Urol (1996);155:1847-51