Vitamin B1 is mostly referred to by the name thiamine now, though it was previously simply known as one of the 8 water soluble B vitamins. It holds the distinction of being the first organ compound to gain recognition as a vitamin.
The bodily functions thiamine is involved includes electrolyte flow in and out of muscle and nerve cells, the functioning of the muscles and nervous system, a number of enzyme processes, producing hydrochloric acid needed for good digestion. It is intrinsic to the body’s production of energy and without it, the body would be unable to convert sugars into usable energy. Vitamin B1 is also vital for the brain to function properly.
Many foods contain trace amounts of this vitamin but the following foods contain more significant amounts: legumes such as lentils and beans, nuts, beef, milk, tuna, oats, brewer’s yeast, yeast, pork, oranges, whole cereal grains, wheat, seeds, green vegetables such as asparagus and spinach, and rice. Foods that are processed, such as white rice and white flour, will often have thiamine added because the natural vitamin is processed out.
Vitamin B1 is not stable and can be easily damaged by several factors. If food becomes too acid, has sulfites or nitrites added, exposed to heat for very long or kept refrigerated long term, it loses a substantial amount of thiamine. As much as possible, food should be eaten fresh and raw or only lightly cooked to obtain the highest amount of thiamine from the food.
Because it is water soluble, not much thiamine is stored so it can deplete rather quickly in about fourteen days. Though it doesn’t happen often, a deficiency that is chronic and severe is called beriberi. Serious complications can result from beriberi that affect the heart, brain, muscles, nervous system and the gastrointestinal system. Other conditions that can result from thiamine deficiency are Korsakoff’s psychosis, Wernicke’s encephalopathy and Wernicke-Korsakoff syndrome. Severe alcoholism can deplete the body of vitamin B1 and cause a deficiency. Increased thiamine intake is the usual method of treatment for conditions resulting from thiamine deficiency.
To date, a toxic level of thiamine has not been found. High doses have been used to treat conditions such as maple sugar urine disease and alcoholism. As of 1998, no upper limit of tolerance has been established.
Of all the B vitamins, B1 is the most dependent on other B vitamins. Without enough folic acid, B6 and B12, thiamine cannot be absorbed as it should be and without enough B12, there can be more thiamine loss through urine. B6 seems to assist in the distribution of thiamine through the body.
This vitamin is easy to get enough of through food intake so supplementation is not usually necessary. However, since it does not have a toxic level, taking additional thiamine in supplements is not harmful and can be beneficial.