Thiamin

Thiamine/Nutrient Depletion:

  • AlcoholAlcohol: Heavy use of alcohol may lead to thiamine deficiency and Wernicke's encephalopathy. Thiamine administration is required. The reasons for thiamine deficiency associated with alcoholism include inadequate intake, decreased conversion of thiamine to its active coenzyme (thiamine pyrophosphate), and reduced absorption, storage, and transport (203; 204; 205; 206). Scientists have suggested that genetic predisposition to thiamine deficiency may contribute to alcoholism-associated dysfunction of the brain and other organ systems (207; 208; 209; 210; 211).
  • AntacidsAntacids: According to secondary sources, antacids may lower thiamine levels in the body by decreasing absorption and increasing excretion or metabolism.
  • AntibioticsAntibiotics: According to secondary sources, antibiotics destroy gastrointestinal flora (normal bacteria in the gut), which manufacture some B vitamins. In theory, this may decrease the amount of thiamine available to humans, although the majority of thiamine is obtained through the diet (not via bacterial production).
  • BarbituratesBarbiturates: According to secondary sources, barbiturates may lower thiamine levels in the body by decreasing absorption and increasing excretion or metabolism.
  • Betel nutsBetel nuts: In human research, consumption of betel nuts (Areca catechu L.) reduced thiamine activity due to chemical inactivation, and it may lead to symptoms and signs of thiamine deficiency (251).
  • Blood glucoseBlood glucose: Although thiamine supplementation lacks an effect on blood sugar levels in humans (167), impaired glucose tolerance may be associated with thiamine deficiency.
  • Carbonated beveragesCarbonated beverages: According to secondary sources, carbonated beverages may decrease the effects of thiamine in the body.
  • Citrate-containing foods or beveragesCitrate-containing foods or beverages: According to secondary sources, foods or beverages with citrates may decrease the effects of thiamine in the body.
  • DichloroacetateDichloroacetate: According to a review, dichloroacetate may cause a reversible peripheral neuropathy that may be related to thiamine deficiency and may be improved with thiamine supplementation (229).
  • DiureticsDiuretics: Thiamine supplementation is often suggested in persons using diuretics, due to increased urinary loss (230; 231; 232; 233). Loop diuretics, particularly furosemide (Lasix?), have been associated with decreased thiamine levels in the body by increasing urinary excretion (and possibly by decreasing absorption and increasing metabolism) (234). Examples of other loop diuretics include bumetanide (Bumex?), ethacrynic acid (Edecrin?), and torsemide (Demadex?). Theoretically, this effect may also occur with other types of diuretics, including thiazide diuretics, such as chlorothiazide (Diuril?), chlorthalidone (Hygroton?, Thalitone?), hydrochlorothiazide (HCTZ, Esidrix?, HydroDIURIL?, Oretic?, Microzide?), indapamide (Lozol?), and metolazone (Zaroxolyn?), and potassium-sparing diuretics, such as amiloride (Midamor?), spironolactone (Aldactone?), and triamterene (Dyrenium?). Effects may be most pronounced with larger doses taken over extended periods of time.
  • HorsetailHorsetail: The potential antithiamine effects of horsetail (Equisetum arvense L.) have been discussed in a review (252). According to secondary sources, horsetail contains a thiaminase-like compound that may destroy thiamine in the stomach and theoretically may cause symptomatic thiamine deficiency. Horsetail products are available without this property, and, for example, the Canadian government requires that horsetail products be certified free of thiaminase activity.
  • MetforminMetformin: In theory, metformin may reduce thiamine activity
  • Oral contraceptivesOral contraceptives: According to review data, use of oral contraceptives may increase risk of thiamine deficiency (248).
  • PhenytoinPhenytoin: According to secondary sources, reduced levels of thiamine in blood and cerebrospinal fluid have been reported in individuals taking phenytoin (Dilantin?) for extended periods of time.
  • Raw seafoodRaw seafood: Raw freshwater fish and shellfish contain thiaminase enzymes that destroy thiamine. According to secondary sources, frequent ingestion of raw fish or shellfish may contribute to thiamine deficiency. Cooking destroys these enzymes, and therefore consumption of cooked seafood does not appear to affect thiamine levels.
  • SucroseSucrose: Although sucrose was theoretically thought to deplete the body of nutrients such as thiamine, there is a lack of evidence in support of this (257).
  • Tannin-containing beverages (coffee, tea)Tannin-containing beverages (coffee, tea): According to secondary sources, chronic intake of polyphenols such as tannins in coffee and tea may convert thiamine to an unabsorbable and inactive form and theoretically may worsen or cause thiamine deficiency. However, this interaction does not appear to be clinically relevant in industrialized countries, where most individuals consume adequate dietary thiamine and ascorbic acid (which prevents this interaction). This interaction has been described in Asian populations that chew fermented tea leaves.
  • Thyroid hormoneThyroid hormone: According to a review, thiamine uptake is reduced by thyroid hormone (249).
  • TobaccoTobacco: According to secondary sources, tobacco use decreases thiamine absorption and may lead to decreased levels in the body.