Vitamins are essential for life, and their total lack would inevitably lead to death. This is because they are involved in specific enzymatic reactions necessary for the production of vital substances. Reading the Roche document on VITAMINS, I noticed that the main deficiencies concern the HEAT-STABLE VITAMINS. Among these, THIAMINE or VITAMIN B1 is the most sensitive to heat and the most commonly deficient. It is estimated that 95% of the population has a mild deficiency and 30% a more significant deficiency.
Vitamin B1 deficiency was known in China as early as 2500 years ago under the name of BERI-BERI. This disease emerged when rice, the main food source, began to be stripped of its outer layer. Vitamin B1 is present in the outer part and in the germ of rice; if these parts are removed, the amount of Vitamin B1 in rice becomes very low and disappears completely during cooking, unless the rice is wholegrain, where it can be preserved, even after cooking, at a dose of 0.5 mg/100 gr. Only in 1910, Funk succeeded in isolating Vitamin B1 from the outer part of rice.
Vitamin B1 or Thiamine is found in high concentrations in Brewer's Yeast, in the pericarp and in the germ of cereals. In smaller quantities it is present in meat, legumes, potatoes, fruit and egg yolk (from 0.1 to 1 mg/100 gr), while it is practically absent in milk. The daily requirement is about 1.6 mg.
An important aspect to consider is that 90% of Thiamine is lost during cooking; therefore, common pasta contains only 0.007 mg/100 gr, as does hulled rice, while brown rice still contains 0.5 mg/100 gr. Fruit, even if eaten raw, is low in Thiamine (apples, pears, peaches, apricots, bananas contain from 0.01 to 0.15 mg/100 gr). Packaged foods are generally sterilized (heated to 120°), and therefore devoid of Thiamine.
Meat contains on average 0.1-0.2 mg/100 gr, provided it is not cooked, since in this case Thiamine is largely lost. Only Brewer's Yeast contains significant quantities, from 2.5 mg to 10 mg/100 gr.
Thiamine is essential for the metabolism of CARBOHYDRATES (SUGARS), facilitating the degradation of GLUCOSE (coming from simple sugars, complex sugars or starches) in the KREBS CYCLE to produce energy; this occurs through a series of complex enzymatic reactions known as the PENTOSE PATHWAY. This pathway is also responsible for the formation of NUCLEOTIDES and NUCLEIC ACIDS. In addition, NADP (ADENIDIN NUCLEOTIDE PHOSPHATE) is formed which favors the synthesis of FATTY ACIDS and STEROIDS.
Vitamin B1 is also essential for the transmission of nerve impulses, considering that the nervous system uses exclusively sugars as a source of energy.
A mild Thiamine deficiency can lead, as a first symptom, to MUSCLE CRAMPS (due to the formation of lactic acid). A more marked deficiency can cause ANOREXIA, REDUCED APPETITE, GROWTH DELAY, DECREASE IN BODY WEIGHT, and ASTHENIA.
A severe deficiency can cause POLYNEURITIS, CONVULSIONS, PARALYSIS, HEAD RETRACTION and, at the cardiovascular level, BRADYCARDIA, DILATED CARDIOPATHY, OXYGEN REDUCTION, EDEMA AND CYANOSIS. In addition, KARSAKOFF SYNDROME can manifest itself with SEVERE MENTAL DISTURBANCES, HALLUCINATIONS, DISORIENTATION, AMNESIA and POLYNEURITIS WITH FREQUENT PARALYSIS. Alcoholism can also cause a severe Thiamine deficiency. The medical community often overlooks the importance of Thiamine and its severe deficiency in the population.
The recommended daily intake of Vitamin B1 should be at least 1.6 mg, but in case of severe deficiency, high doses can be used, even up to 500 mg per day orally or intravenously, without side effects, since the body uses what it needs and eliminates the rest through urine.
It is important to note that there are also factors that inactivate Vitamin B1, called THIAMINASES, which can be present in the flesh of some fish, thus explaining the high number of cases of BERI-BERI in some regions of Japan.