What metabolic disorders are caused by thiamine deficiencies?
What metabolic disorders are caused by thiamine deficiencies?
Thiamin deficiency (causing beriberi) is most common among people subsisting on white rice or highly refined carbohydrates in developing countries and among alcoholics. Symptoms include diffuse polyneuropathy, high-output heart failure, and Wernicke-Korsakoff syndrome.
How does thiamine deficiency affect metabolism?
If sufficiently prolonged and severe, thiamine deficiency results in brain cell death. Possible mechanisms involved include compromised cerebral energy metabolism and focal accumulation of lactate, both of which could result from decreased activities of alpha KGDH.
What would be the impact of low vitamin b1 thiamine in lactic acid levels?
Severe thiamine deficiency can trigger acute lactic acidosis [8]. Thiamine functions as a cofactor in mitochondrial oxidative decarboxylation, converting pyruvate to acetyl-CoA and α-ketoglutarate to succinyl-CoA for use in the citric acid (Krebs) cycle [9].
What is the richest source of thiamin?
Food. Food sources of thiamin include whole grains, meat, and fish [2]. Breads, cereals, and infant formulas in the United States and many other countries are fortified with thiamin [2]. The most common sources of thiamin in the U.S. diet are cereals and bread [8].
Does thiamine deficiency affect brain?
A deficiency of a single vitamin, B1 (thiamine), can cause a potentially fatal brain disorder called Wernicke encephalopathy. Symptoms can include confusion, hallucinations, loss of muscle coordination and vision problems. Untreated, the condition can lead to irreversible brain damage and death.
Why does thiamine deficiency affect the brain?
Several mechanisms have been proposed to explain this selective loss of neurons including a cerebral energy deficit resulting from reductions in activity of thiamin diphosphate-dependent enzymes, oxidative stress and N-methyl-D-aspartate receptor-mediated excitotoxicity.
Why does thiamine deficiency lead to lactic acidosis?
Lack of thiamine can lead to potentially life-threatening events. Inadequate stores of thiamine result in the failure of pyruvate to enter the tricarboxylic acid cycle, thus preventing aerobic metabolism, which may lead to profound lactic acidosis through anaerobic metabolism.
What happens if you get too much of thiamine?
Loss of feeling (sensation) in the hands and feet. Loss of muscle function or paralysis of the lower legs. Mental confusion/speech difficulties. Pain.
Is there a link between thiamine deficiency and lactic acidosis?
Physicians who prescribe TPN should recognize the potential risks for acute thiamine deficiency and lactic acidosis in patients who are not receiving adequate supplements. Until the manufacture of MVIs for TPN for adults increases, shortages of these products may continue.
What are the side effects of thiamine deficiency?
This report details the case of a female patient with severe thiamine deficiency secondary to dysphagia caused by radiation injury. She developed debilitating polyneuropathy and cardiomyopathy with decreased ejection fraction.
Why is lactic acidosis rare in the body?
In the absence of thiamine this reaction cannot proceed and instead, pyruvate is converted to lactate. The resulting accumulation of lactate causes lactic acidosis. Lactic acidosis due to thiamine deficiency is rare because thiamine deficiency is rare.
Who is at risk for thiamine deficiency without MVI?
Patients receiving TPN without MVI supplementation are at risk for thiamine deficiency and life-threatening complications associated with severe deficiency of thiamine, a coenzyme necessary for oxidation of keto acids ( Figure_1 ).
