Antiacids. These medications may lower thiamin
levels in the body by decreasing absorption and
increasing excretion or metabolism.
Tetracycline. Tetracyline is an antibiotic and thiamin
taken either alone or in combination with other B
vitamins interferes with its absorption by the body
and action in the body.
Antidepressants. Thiamin supplements may improve
the action of antidepressants such as nortriptyline,
especially in elderly patients. Other medications in
this class of drugs include desimpramine and
imipramine.
Chemotherapy drugs. Laboratory studies suggest
that thiamin may prevent the activity of chemother-
apy drugs, but effects are not yet understood in
people. Patients undergoing chemotherapy for can-
cer, especially people receiving fluorouracil-contain-
ing drugs, are usually advised not take large doses of
vitamin B 1 supplements.
Diuretics. Diuretics, especially furosemide, which
belongs to a class of drugs called loop diuretics,
may reduce the levels of thiamin in the body.
Digoxin. Laboratory studies also suggest that
digoxin, a drug used to treat heart conditions, may
lower the ability of heart cells to absorb and use
thiamin, especially if digoxin is combined with
furosemide.
Scopolamine. Thiamin may help reduce some of the
side effects associated with scopolamine, a drug used
to treat motion sickness.
Thiamin can also interact with food substances.
Foods and beverages that may inactivate thiamin
include those containing sulfites and tea, coffee and
decaffeinated coffee. Consumption of betel nuts may
also reduce thiamin activity due to chemical inactiva-
tion, and may lead to symptoms of thiamin deficiency.
Tobacco use also decreases thiamin absorption and
may lead to decreased levels in the body.AftercareAll forms of thiamin deficiency are treated with
supplements. If severe deficiency results in a medical
emergency, it is treated with high doses of thiamin for
several days. When alcoholics must be fed intrave-
nously, they are often given supplements as a preven-
tive measure. Doses for conditions, such as severe
beriberi or alcoholism, are administered by a health
care practitioner in an appropriate clinical setting. The
symptoms of beriberi may recur years after apparent
recovery.Complications
Brain abnormalities due to thiamin deficiency are
complications that occur mainly in alcoholics. They
may develop when a chronic thiamin deficiency is
suddenly worsened by a rapid decrease in the thiamin
levels by an alcoholic binge or by a sudden increase in
thiamin requirements when a malnourished alcoholic
is fed intravenously. Brain abnormalities may develop
in two stages: an early stage (Korsakoff’s syndrome)
and a later stage (Wernicke’s encephalopathy).
Together, they are called the Wernicke-Korsakoff syn-
drome. Korsakoff’s syndrome causes memory loss,
and Wernicke’s encephalopathy causes mental confu-
sion, difficulty walking, and eye problems. If Wer-
nicke’s encephalopathy is not treated, symptoms may
lead to coma and even death. As for excessive thiamin
intake complications, rare hypersensitivity/allergic
reactions have occurred with supplementation.Parental concernsParents should refrigerate fresh produce and keep
milk and grains away from strong light because vita-
mins are easily destroyed and washed out during food
preparation and storage. Vitamin supplements should
also be stored at room temperature in a dry place.
Taking thiamin for a long period of time can
result in an imbalance of other B-complex vitamins.
This is why it is generally recommended to take a B-
complex vitamin with thiamin. Because of the poten-
tial for side effects and interactions with medications,
thiamin supplements should also be taken only under
the supervision of a knowledgeable health care
provider.Resources
BOOKS
Berkson, B., Berkson, A. J.User’s Guide to the B-complex
Vitamins.Laguna Beach, CA: Basic Health Publica-
tions, 2000.
Carpenter, K.Beriberi, White Rice, and Vitamin B: A Dis-
ease, a Cause, and a Cure.Berkeley, CA: University of
California Press, 2000.
Challem, J., Brown, L.User’s Guide to Vitamins & Minerals.
Laguna Beach, CA: Basic Health Publications, 2002.
Garrison, R., Somer, E.The Nutrition Desk Reference.New
York, NY: McGraw-Hill, 1998.
Griffith, H. W.Minerals, Supplements & Vitamins: The
Essential Guide.New York, NY: Perseus Books Group,
2000.
Institute of Medicine.Dietary Reference Intakes for Thiamin,
Riboflavin, Niacin, Vitamin B 6 , Folate, Vitamin B 12 ,
Pantothenic Acid, Biotin, and Choline.Washington,
DC: National Academies Press, 2000.Thiamin