Supplements
Vitamin B1 (Thiamine)
Vitamin B1 (thiamine) is a water-soluble vitamin. Intake of vitamin B1 is required on a regular basis due to the body's inability to store it in large amounts. Like all the B-complex vitamins, any excess is excreted and not stored in the body. It must be replaced daily. B vitamins are most potent when they are taken together. B1, B2, and B6 should be equally balanced to work effectively (i.e., 75mg. of B1, 75mg. of B2, 75 mg. of B6).
Thiamine enhances and assists in blood formation, production of hydrochloric acid, which is important for proper digestion, and carbohydrate metabolism.
Thiamine also works on the brain function for optimal cognitive activity. It enhances energy, growth, learning and normal appetite.
Vitamin B1 is key for proper muscle tone of the intestines, stomach, and heart. B1 also acts as an antioxidant, protecting against aging, alcohol consumption and smoking.
Thiamine is necessary for treatment of depression, diarrhea, mental illness, stress, beriberi, shingles, anemia, and infections. A diet high in carbohydrates increases the need for thiamine.
Vitamin B1 can be taken postoperatively for pain from dental procedures, to relieve air or seasickness and in the treatment of herpes zoster.
Deficiency: The disease of vitamin B1 deficiency is called beri beri. Beri beri is characterized by neurological symptoms ('dry' beri beri) and cardiovascular symptoms ('wet' beri beri). Beri beri became widespread in East Asia in the nineteenth century when polished rice, which lacked the vitamin B1-rich husks, became a diet staple.
Symptoms of dry beri beri include peripheral neuritis with sensory disturbances in the extremities, convulsions, exaggeration of tendon reflexes, and the "burning feet syndrome." This is usually observed in chronic alcoholics. Chronic alcoholics with these symptoms should receive up to 40 mg of oral vitamin B1 daily.
In some patients, vitamin B1 deficiency affects the gastrointestinal tract. When this occurs, vitamin B1 replacement can relieve symptoms such as ulcerative colitis, diarrhea, and gastrointestinal hypotonia.
Wernicke's encephalopathy, is a vitamin B1 deficiency that affects the central nervous system. Classic symptoms are confusion, ophthalmoplegia, nystagmus, and ataxia. A typical treatment consists of 100 mg of intravenous vitamin B1 daily for three days. If left untreated, Wernicke's encephalopathy can lead to Korsakoff's psychosis, which is characterized by confabulation and in most cases is not treatable once established.
Neuritis of pregnancy is caused by hyperemesis gravidarum or low vitamin B1 intake. If vitamin B1 deficiency is the cause of the neuritis, clinical improvement will be seen following vitamin B1 therapy. A typical therapeutic regimen is 5 to 10 mg of vitamin B1 daily, given parenterally if vomiting is severe.
Deficiency: Symptoms that can result from B1 deficiency include constipation, edema, fatigue, forgetfulness, enlarged liver, irritability, labored breathing, loss of appetite, gastrointestinal disorders, nervousness, numbness of the hands and feet, pain and sensitivity, poor coordination, tingling sensations, weak and sore muscles, severe weight loss and general weakness.
Depleting Agents: Stress, caffeine, surgery, excess carbohydrate consumption (sugar), tobacco, raw fish and shellfish, antibiotics, phenytoin (Dilantin, a drug used to prevent seizures), sulfa drugs, oral contraceptives, sulfa drugs, muscle relaxants.
Sources: Brown rice, egg yolks, fish legumes, liver, peanuts (unroasted), peas, pork, poultry, sunflower seeds, soybeans, rice bran, whole wheat, wheat germ and whole grains. Additional sources are asparagus, brewer's yeast, broccoli, Brussels sprouts, dulse, kelp, spirulina, oatmeal, plums, dried prunes, raisins, and watercress.
Herb Sources: Alfalfa, bladderwrack, burdock root, catnip, cayenne, chamomile, chickweed, eyebright, fennel seed, fenugreek, hops, nettle, oat straw, parsley, peppermint, raspberry leaf, red clover, rose hips, sage yarrow, and yellow dock.
Precautions: There is no known toxicity for Vitamin B1. However excessive dosing (exceeding 5-10g. daily) may cause symptoms of tremors, herpes, edema, nervousness, rapid heartbeat, and allergies.
Special Note: Recent studies suggest a role for vitamin B1 in the management of congestive heart failure. Patients given the loop diuretic furosemide may be at greater risk for vitamin B1 deficiency through urinary loss, which can lead to wet beri beri and can contribute to cardiac insufficiency. In these patients, supplementation with thiamine results in improved cardiac conditions.
Vitamin B1 may also play a negative role in cancer chemotherapy. Researchers have found that the overadministration of vitamin B1 to chemotherapy patients may aid the tumor cells by providing ribose via transketolation as a substrate for nucleic acid synthesis and ultimately tumor growth. Vitamin B1 may play a role in failed chemotherapy in cancer patients who receive doses that are 200-fold over the RDA.
Congenital defects: Maple syrup disease, congenital lactate acidosis, subacute necrotizing encephalopathy, and vitamin B1-responsive megaloblastic anemia are inherited diseases with congenital defects in vitamin B1 metabolism. Vitamin B1 therapy has been reported to improve these conditions.
Dosage Ranges and Duration of Administration:
- Neonates to 6 months: 0.3 mg/day
- Infants 6 months to 1 year: 0.4 mg/day
- Children 1 to 3 years: 0.7 mg/day
- Children 4 to 6 years: 0.9 mg/day
- Children 7 to 10 years: 1.0 mg/day
- Boys over 11 years, men 18 to 50 years: 1.5 mg/day
- Men over 50 years: 1.2 mg/day
- Girls over 11 years, women 18 to 50 years: 1.1 mg/day
- Women over 50 years: 1.0 mg/day
- Pregnant women: 1.5 mg/day; lactating women: 1.6 mg/day.
INTERACTIONS
Nortriptyline
Supplementation with vitamins B1, B2, and B6 (10 mg each) at the start of tricyclic antidepressant therapy improved cognitive functioning and depression ratings in 14 geriatric patients undergoing treatment with nortriptyline titrated to doses yielding blood levels between 50 to 150 ng/mL. B vitamins may augment the treatment of depression in elderly patients.
Scopolamine
In a randomized, double-blind, placebo-controlled, double-crossover clinical trial with 13 healthy subjects, coadministration of thiamine (5 g po) countered the cognitive side effects associated with scopolamine treatment (0.007 mg/kg IM) as compared to placebo.
Tetracycline
In one study, the bioavailability of tetracycline hydrochloride was reduced significantly by concomitant administration of vitamin B complex to healthy subjects. Patients should be cautioned to take vitamin B complex supplements at different times from tetracycline.
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