2.11d Riboflavin and Thiamine

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2.11d: Riboflavin and Thiamine

Update  29 Nov. 2021.  Riboflavin, or Vitamin B2

Riboflavin, or Vitamin B2, is involved in oxidation-reduction and assists anti-oxidants.

Riboflavin food source: egg, lean meat, broccoli, enriched bread and cereal. In USA, food staples are fortified with riboflavin.  

Human experiment using riboflavin-lacking diet or riboflavin antagonist showed deficiency syndrome of sore throat, inflamed, reddened tongue, mouth-ulcer, and lip corner fissure, seborrheic dermatitis (dandruff scalp and scaly May skin), and red blood cell anemia of normal size and color cells. Riboflavin deficiency is seen only in severely malnourished person and associated with other deficiencies of B-complex (Thiamine B₁, Niacin B₃, pyridoxine B₆, folic acid and cobalamin B₁₂).

   Riboflavin deficiency from genetic inborn error can be diagnosed by pediatrician shortly after birth, and is helped by high dose of riboflavin daily. It is seen in infants also as part of the deadly Reye's syndrome from aspirin treatment of virus-caused fever and is partly treated with riboflavin.
   Megavitamin riboflavin has been tried much with no success.  

Thiamine or Vitamin B₁

Thiamin(e) (Vitamin B₁) in vitamin pill is the hydrochloride (Th-HCl). Its food source is yeast, pork, and bean. In cereal grain (rice, wheat), thiamine is mostly located in the germ or brown husk and not in the much larger, central body. (Hence, beriberi from eating only white rice!) Otherwise it is not high in food, explaining why beriberi was widespread before vitamin fortification.

Food processing destroys thiamine, particularly prolonged cooking, canning, and baking (but not freezing). Pasteurization and other food sterilization destroy it; and, since it is water soluble, even rinsing fortified white rice before cooking results in its loss. Staple foods in the U.S. are fortified so Americans with good appetite do not need to worry about thiamine.

 Alcohol lowers intestinal thiamine uptake; so, heavy alcohol drinker is at risk for the deficiency. 
Thiamine is closely involved in release of energy to tissue cell from oxidation of glucose and fatty acid. It is important in nerve conduction. Its deficiency syndrome is seen in beriberi, either heart failure with rapid heart rate and massive swelling (wet beriberi) or loss of nerve function and brain disease (dry beriberi) including memory loss. Early sign: rapid heart (≧100 beats/min) at rest, easy fatigue, and pin and needle feeling in hand and foot.

Who is at Risk? Alcoholic, homeless, prolonged fasting and breast-fed infant of deficient mother.

Thiamine is very important in acute alcoholism. Adequate intake will prevent permanent damage and there is no upper limit to the intake. 

There is no easy blood test for thiamine.

Medicinal & Megavitamin Use: Genetic inborn error requires lifetime high-dose injected thiamine, it shows severe symptom shortly after birth. Treatment of alcoholism requires daily dose thiamine. The chronic alcoholic (or the non alcoholic with persistent vomiting) exhausts his body supply of thiamine in 7 or 8 weeks during which time glucose IV infusion may suddenly evoke a thiamine deficiency syndrome that could kill. So doctors give 100 mg or more of thiamine daily to alcoholics or other severely malnourished persons seen in emergency.  High-dose daily thiamine is treatment of beriberi. Alcoholics should take daily thiamine supplement.
 Megavitamin doses have been tried much for schizophrenia and manic depression, but no identifiable result.

Chapter Continues click 2.11e Everything you need to read on vitamin A