Thiamine

These slides containing a brief introduction of thiamine including diseases caused by its deficiency.

1. Thiamine (Vitamin B 1 ) Komal Soni M.sc.(Deptt. Of Nutrition Biology) 2 nd Semester Central University of Haryana 1

2. Contents Introduction Chemistry of Thiamine Functions Sources Absorption Transportation Storage Excretion Deficiency Common symptoms of thiamine deficiency Some researches on Thiamine 2

3. Introduction Thiamine is also known as vitamin B1, anti Beri-Beri vitamin. Discovered by Christian Eijkman in 1897. Water –soluble. Needed on daily basis. Non-toxic. Plays critical role in energy production. Required as co-enzyme. 3

4. Chemistry of Thiamine White, water soluble crystalline solid. It’s an organosulphur compound having formula C 12 H 17 ON 4 S Structure consists of an aminopyrimidine & thiazolium ring linked by a methylene bridge. Stable at acidic pH, destroys at alkaline pH. 4

5. Functions Precursor of co-enzyme TPP(Thiamine pyro phosphate). Stimulate appetite. Normal nerve function by providing energy. Synthesize & regulate neurotransmitters (myelin sheath production) Cure Beri-Beri. Proper function of heart muscles. Formation of RBCs Healthy mucus membrane. 5

6. Sources Plant sources Vegetables Cereals Pulses Nuts Oil seeds Orange & tomato juices Animal sources Milk Pork Egg Poultry Fish 6

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8. Absorption Most of the absorption of thiamine occurs in the jejunum & ileum of small intestine. If thiamine is consumed in small amounts, is absorbed by sodium dependent active transport mechanism. If large amounts are consumed, passive diffusion takes place. Thiamine as TPP within food must be dephosphorylated to thiamine before absorption. TPP is then reformed from thiamine & phosphate within cells whenever required. 8

9. 9 Thiamine Pyrophosphatase Thiamine Monophosphatase Thiamine Pyrophosphokinase

10. Transportation Thiamine is transported via blood. Majority of thiamine is bound to protein Albumin. Approx. 90% of total thiamine in blood is in erythrocytes. Thiamine-Binding Protein (TBP) is important for tissue distribution of thiamine. 10

11. Storage Very low Thiamine is stored in liver & erythrocytes in the form of TPP. When circulating thiamine levels decrease , the stored TPP TMP Thiamine Released into the circulation 11

12. Excretion Excess thiamine is excreted in urine. Mainly excreted as thiamine & TMP. Other acid metabolites are: 2-methyl-4-amino-5-pyrimidine carboxylic acid 4-methyl-thiazole-5-acetic acid Thiamine acetic acid 12

13. Deficiency 13 When healthy individuals are deprived of Thiamine, thiamine stores are depleted within one month. Within a week after thiamine intake stops : tachycardia, weakness, decreased tendon reflexes, some develops diseases.

14. Deficiency Diseases 14

15. Wet Beri- Beri Affects cardiovascular system. Pathophysiology : 15

16. Symptoms: Dyspnea Orthopnea Increased heart rate Pulmonary edema Swelling in legs 16

17. Dry Beri- Beri Affects central nervous system. Causes peripheral neuropathy with myelin degeneration. Thiamine helps in myelin sheath production. Symptoms: Difficulty in walking Paralysis in lower legs Mental confusion 17

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19. Infantile Beri- Beri It occurs in infants between 2-5 months of age( who are fed only breast milk) & whose mothers are thiamine deficient. The affected baby develops cyanosis ( skin turns blue due to lack of oxygen), tachycardia, vomiting & convulsions. Cyanosis becomes visible when there is >3-5g/dl of deoxygenated hemoglobin. 19

20. 20 Cyanosis

21. Wernicke- Korsakoff Syndrome Consumption of excessive alcohol can lead to malnutrition & poor absorption of thiamine. Sometimes reason may be Bariatric surgery (Gastrectomy). 21 Wernicke’s encephalopathy Korsakoff’s syndrome Language problem Unusual eye movements Mental confusion Memory loss Impaired ability to learn Confabulation( making up stories)

22. Common symptoms of thiamine deficiency Tachycardia Numbness in legs & hands Edema Weakness Mental confusion 22

23. Some researches on Thiamine 23 Helps in treatment of Lactic Acidosis

24. 24 Vascular complications in Diabetes

25. In diabetic patient, endothelial glycocalyx layer damages so can’t restrict albumin excretion. 25 Thiamine could reverse early kidney diseases in Diabetes

26. Consuming high thiamine (300mg/day) will reduce the excretion of albumin. 26

27. Consumption of Thiamine fortified Fish Sauce by pregnant women for 6 months – reduces chances of infantile beri - beri . 27 Thiamine fortified Fish Sauce help fight Infantile Beri-Beri in Southeast Asia.

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