Vitamin B1 (Thiamin)
Description
Thiamine is synthesized in bacteria and plants while animals must obtain it from their diet.
Function
Vitamin B1 (in its thiamin pyrophosphate form) is a coenzyme for four enzymes involved in carbohydrate and lipid metabolism. As such, it plays a central role in the production of energy from sugars, starch, and other molecules. Thiamin is also involved in the production of five-carbon sugars required for synthesis of DNA and RNA, as well as playing a role in fatty acid synthesis. In yeast, ThDP is also required in the first step of alcoholic fermentation
Deficiency
Thiamin deficiency may occur in chronically ill or malnourished patients (e.g., malnutrition, hemodialysis, alcoholism etc.); it may also happen in persons following strict diets high in unenriched or polished white rice or flour. Deficiencies may lead to neurological and cardiac complications. Typical neurological complications include beriberi (characterized by peripheral neuropathy, cardiac problems and swelling of the extremities), Wernicke’s encephalopathy (characterized by ataxia, dysarthria and nystagmus), Korsakoff’s syndrome (characterized by confabulation).
Recent research indicates that thiamin deficiency is also prominent in pregnancy, warranting increased thiamin supplementation for women who are currently pregnant or expecting to become pregnant.
Sources
Dietary sources of thiamin include whole grain products (probabbly the most important source), beef, pork, and yeast. In industrialized countries, thiamin in often added to cereals and foods made with white rice or white flour.
Toxicity
Taken orally, thiamin is generally considered safe; even very high oral doses of thiamin have not been found to have dangerous adverse effects.
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Scientific References
Books
Thiamin. Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B6, Vitamin B12, Pantothenic Acid, Biotin, and Choline, Food and Nutrition Board, Institute of Medicine, Washington D.C.: National Academy Press; 1998:58-86.
Thiamin, Rindi G., In: Present Knowledge in Nutrition. 7th ed., Ziegler EE, Filer LJ, eds., Washington D.C.: ILSI Press; 1996:160-166.
Thiamin, Tanphaichitr V., In: Modern Nutrition in Health and Disease. 9th ed., Shils M, Olson JA, Shike M, Ross AC, eds., Baltimore: Williams & Wilkins; 1999:381-389.
Scientific Articles
Alterations of thiamine phosphorylation and of thiamine-dependent enzymes in Alzheimer's disease, Heroux M, Raghavendra Rao VL, Lavoie J, Richardson JS, Butterworth RF., Metabolic Brain Disease, 1996;11(1):81-88.
[Abstract]
Brain energy metabolizing enzymes in Alzheimer's disease: alpha-ketoglutarate dehydrogenase complex and cytochrome oxidase, Kish SJ., Annals of the New York Academy of Sciences, 1997;826:218-228.
[Abstract]
Brain thiamine, its phosphate esters, and its metabolizing enzymes in Alzheimer's disease, Mastrogiacoma F, Bettendorff L, Grisar T, Kish SJ., Annals of Neurology, 1996;39(5):585-591.
[Abstract]
Diet and cataract: the Blue Mountains Eye Study, Cumming RG, Mitchell P, Smith W., Ophthalmology, 2000;107(3):450-456.
Diuretic use: a risk for subclinical thiamine deficiency in elderly patients, Suter PM, Haller J, Hany A, Vetter W., Journal of Nutrition, Health & Aging, 2000;4(2):69-71.
[Abstract]
Do diuretics cause thiamine deficiency?, Wilcox CS., The Journal of Laboratory and Clinical Medicine, 1999;134(3):192-193.
Improved left ventricular function after thiamine supplementation in patients with congestive heart failure receiving long-term furosemide therapy, Shimon I, Almog S, Vered Z, et al., American Journal of Medicine, 1995;98(5):485-490.
[Abstract]
Interactions between drugs and vitamins at advanced age, Schumann K., International Journal for Vitamin and Nutrition Research, 1999;69(3):173-178.
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Is there a role for thiamine supplementation in the management of heart failure?, Leslie D, Gheorghiade M., American Heart Journal, 1996;131(6):1248-1250.
[Abstract][Full Text][Full Text PDF]
Is thiamine deficiency in elderly people related to age or co-morbidity?, Wilkinson TJ, Hanger HC, George PM, Sainsbury R., Age and Ageing, 2000;29(2):111-116.
Long-term nutrient intake and 5-year change in nuclear lens opacities., Jacques PF, Taylor A, Moeller S, et al., Archives of Ophthalmology, 2005;123(4):517-526.
[Abstract]
Mechanisms of selective neuronal cell death due to thiamine deficiency, Todd K, Butterworth RF., Annals of the New York Academy of Sciences, 1999;893:404-411.
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Nutritional Biochemistry. 2nd ed., Brody T., San Diego: Academic Press; 1999,
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Optimum nutrition: thiamin, biotin and pantothenate., Bender DA., Proceedings of the Nutrition Society, 1999;58(2):427-433.
PDR for Nutritional Supplements, Hendler SS, Rorvik DR, eds., Montvale: Medical Economics Company, Inc; 2001.
[Abstract]
Preliminary findings of high-dose thiamine in dementia of Alzheimer's typ, Meador K, Loring D, Nichols M, et al., Journal of Geriatric Psychiatry and Neurology, 1993;6(4):222-229.
[Abstract]
Reduced concentrations of several vitamins in normal weight patients with late-onset dementia of the Alzheimer type without vascular disease, Glaso M, Nordbo G, Diep L, Bohmer T., Journal of Nutrition, Health & Aging, 2004;8(5):407-413.
[Abstract]
The effect of thiamine supplementation on tumour proliferation. A metabolic control analysis study, Comin-Anduix B, Boren J, Martinez S, et al., European Journal of Biochemistry, 2001;268(15):4177-4182.
Thiamin deficiency in HIV-positive patients: evaluation by erythrocyte transketolase activity and thiamin pyrophosphate effect, Muri RM, Von Overbeck J, Furrer J, Ballmer PE., Clinical Nutrition, 1999;18(6):375-378.
[Abstract]
Thiamin is decomposed due to Anaphe spp. entomophagy in seasonal ataxia patients in Nigeria, Nishimune T, Watanabe Y, Okazaki H, Akai H., Journal of Nutrition, 2000;130(6):1625-1628.
Thiamine deficiency and malaria in adults from southeast Asia, Krishna S, Taylor AM, Supanaranond W, et al., Lancet, 1999;353(9152):546-549.
[Abstract]
Thiamine deficiency and unexplained encephalopathy in hemodialysis and peritoneal dialysis patients, Hung SC, Hung SH, Tarng DC, Yang WC, Chen TW, Huang TP., American Journal of Kidney Diseases, 2001;38(5):941-947.
[Abstract]
Thiamine deficiency in congestive heart failure patients receiving long term furosemide therapy, Zenuk C, Healey J, Donnelly J, Vaillancourt R, Almalki Y, Smith S., Canadian Journal of Clinical Pharmacology, 2003;10(4):184-188.
[Abstract]
Thiamine for Alzheimer's disease, Rodriguez-Martin JL, Qizilbash N, Lopez-Arrieta JM., Cochrane Database Systematic Reviews, 2001;2:CD001498.
[Abstract]
Thiamine supplementation to cancer patients: a double edged sword, Boros LG, Brandes JL, Lee WN, et al., Anticancer Research, 1998;18(1B):595-602.
[Abstract]
Thiamine therapy in Alzheimer's disease, Mimori Y, Katsuoka H, Nakamura S., Metabolic Brain Disease, 1996;11(1):89-94.
[Abstract]
Vitamin requirements of elderly people: an update, Russell RM, Suter PM., American Journal of Clinical Nutrion, 1993;58(1):4-14.
