Vitamin B1

Biochemical action of vitamin B1

Vitamin B1 belonging to the water-soluble vitamins is vital for metabolism. It is ingested through the digestive system and circulates in the blood before being eliminated in the urine. The liver, heart, kidney, and brain have temporary storage spaces for small quantities. Thiamin is a cofactor for the enzymes participating in glycolysis, the Krebs cycle, and the pentose phosphate pathway in its active form, thiamin pyrophosphate (TPP). A thiamin shortage can harm the brain and result in lactic acidosis by inhibiting enzyme function. TPP also helps the erythrocyte transketolase synthesise nucleotides. The relevance of thiamin is shown by how crucial it is for sustaining both brain and general health.

Vitamin B1 is available in tablets, capsules and injectable solutions.

• Tablets/ capsules are to be swallowed whole with water/liquid, as applicable.
• Injectable solutions are to be administered parenterally, as applicable.

Vitamin B1 can be used as a supplement support for-.

• Biosynthesis of neurotransmitters: Acetylcholine and gamma-aminobutyric acid are two neurotransmitters involved in producing thiamin. It may also function in the transmission of nerve impulses similarly to TTP.
• DNA: Thiamin is used more frequently in persons with tumours because it is involved in generating DNA precursors.
• Essential for energy production and metabolism: Thiamin (Vitamin B1) serves as a cofactor in enzymes that break down carbohydrates by converting pyruvate to acetyl CoA, enhancing the actions of transketolase and alpha-ketoglutarate, and promoting the breakdown of amino acids.

Vitamins and natural supplements should not replace a balanced diet

This product is not intended to diagnose, treat or prevent any disease(s).

Vitamin B1 may be useful as a supplement for the following health benefits:

• Alzheimer’s disease: Thiamin insufficiency may have an impact on Alzheimer's-related dementia, according to research being conducted by experts. There has to be more research done to see whether thiamin supplements might improve mental function in those with Alzheimer's disease.
• Hyperthyroidism: Wernicke's encephalopathy is a serious, sometimes fatal condition resulting from hyperthyroidism and alcohol misuse. It can be easily avoided by taking the right amount of thiamine as a supplement.
• Diabetes: Due to thiamine's direct effect on the breakdown of glucose, diabetes has been discovered to be connected with low levels of thiamine stores in the body. According to studies, high-dose thiamine treatment may help treat early-stage diabetic nephropathy.
• Acute alcohol withdrawal: A dosage of 100 mg thiamin given IV or IM before the regular administration of dextrose-containing solutions is recommended by multiple experts for the support of alcohol withdrawal.
• Congestive heart failure (CHF): Thiamine deficiency appears to be prevalent in HF patients. Thiamine supplementation has been proven to enhance cardiac function, urine output, weight loss, and signs and symptoms of HF.
• Epilepsy: Numerous enzymes necessary for the functioning of the brain and the production of neurotransmitters require thiamine as a cofactor. For oxidative stress defences, thiamine-dependent enzymes are essential. According to several studies, thiamine deficiency in the central nervous system lowers the seizure threshold.

• Orally: Vitamin B1 is commonly administered orally before or after meals for all oral solids forms. The dosage and duration of treatment should be as per the clinical judgment of the treating healthcare professional.

• Parenterally: Vitamin B1 supplement is administered intravenously or intramuscularly as instructed by a physician. IV administration is preferable for high-output heart failure when the oral route is not feasible or when malabsorption is indicated in patients with Wernicke's encephalopathy or high-output heart failure caused by Beriberi.

The dosage and duration of treatment should be as per the clinical judgment of the treating healthcare professional.

Vitamins and natural supplements should not replace a balanced diet

This product is not intended to diagnose, treat or prevent any disease(s).

• Tablet: 50mg,100mg, 250mg
• Capsule: 50mg
• Injectable solution:100mg/mL

Dosage Adjustment in Adult Patients

Beriberi

IM: 5 to 30 mg TID (if critically ill); then 5 to 30 mg three times a day for a month.

The duration of therapy depends on the persistence of symptoms.

Wernicke Encephalopathy

100 mg IV; then 50-100 mg/day IM or IV until consuming a regular balanced diet.

Thiamin Deficiency

1 tablet or capsule/day

The need for thiamin increases when the carbohydrate content of the diet is high.

Vitamin B1 is available in the form of tablets, capsules and injections.

• Limit the consumption of foods like blueberries, red cabbage and Brussels sprouts and beverages that include caffeine, such as coffee, tea, chocolate, and alcoholic drinks, as this substance could hinder the absorption of vitamin B1.
• Limit alcoholic beverages.
• Stay within your daily calorie needs.

Recommended Daily Allowance (RDA)

The RDA for adult men is 1.2 mg/day and 1.1 mg/day for women.

Upper Tolerable Intake (UTL):

No UTL is set for thiamine, as data concerning adverse effects are insufficient.

The dietary restriction should be individualized as per patient requirements.

• Use of Dextrose in acute thiamine deficit should be cautious, especially if thiamine status is unknown.
• Individuals with hypersensitivity to vitamin B1 after repeated parenteral doses.
• Aluminium may be present in parenteral preparations; use caution in individuals with poor renal function.
• If a thiamin shortage has been identified in the patient, check for other vitamin deficiencies, and single vitamin deficiency is rare.
• Several human studies show that thiamine's impact on cancer development is unclear.

The treating healthcare professional must closely keep a watch and monitor for signs and symptoms of adverse reactions, such as allergic responses or gastrointestinal disturbances. It is recommended to discontinue the use of vitamin B1 in case of allergies.

Vitamin B1 supplements should be used with caution by people who have kidney problems as they may influence excretion rates.

Caution is advised when consuming alcohol with Vitamin B1.

Safe to use during breastfeeding. Several studies suggest that the drug does not pass into the breastmilk significantly and is not harmful to the baby.

Food may decrease the rate but not the extent of absorption. Limit foods and drinks higher in added sugars, saturated fat, and sodium.

Vitamin B1 supplementation is reported to be well-tolerated and safe to use.

The adverse reactions related to Vitamin B1 can be categorized as-

• Common: Mild stomach upset, gastrointestinal discomfort and allergic reactions, such as skin rash or itching.
• Less common: Hypotension occurs in high iv doses.
• Rare: Anaphylaxis (a severe allergic reaction)

• Antibiotics: Antibiotics inhibit the gut flora's ability to produce B group vitamins, which might hypothetically lower blood levels of B vitamins. Increase your consumption of foods high in vitamin B1, or consider taking supplements, as this may have therapeutic value.
• Vitamin C and citric acid: Foods like lemons, grapefruits, oranges and lemons may enhance oral bioavailability of thiamine.
• Iron: Iron precipitates thiamin, thereby reducing its absorption — separate doses by 2 hours.
• Loop diuretics: Chronic use may result in lowered levels of vitamin B1 — increase intake of vitamin B1-rich foods or consider long-term supplementation.
• Sulfites: Concomitant intake may inactivate thiamin, which has been reported in Total Parenteral Nutrition (TPN) solutions.
• Tannins: Tannins precipitate thiamin, thereby reducing its absorption — separate doses by 2 hours.
• Horsetail (Equisetum arvense): Horsetail has a substance similar to thiaminase, which theoretically may cause the plant to break down thiamin in the stomach. Horsetail use shouldn't be used with thiamin deficiency in anyone who already has it or is at risk of developing it.

The common side effects associated with Vitamin B1 include

• Abdominal pain
• Hives
• Itching
• Warmth
• Nausea
• Anaphylaxis
• Cyanosis
• Diaphoresis
• Restlessness
• Angioneurotic edema
• Pruritus
• Urticaria
• Pulmonary edema
• Weakness
• Tightness of the throat

• Pregnancy: The recommended daily intake of vitamin B1 is 1.4 mg/day.

Pregnancy Category: A (injectable); C (if >RDA)

It is generally safe and acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

• Paediatrics: Vitamin B1 deficiency is higher in children, especially babies; it is critical in promoting brain growth, sustaining cell function, and converting energy from good.

Dosage Adjustment for Paediatric Patients

Deficiency

10-50 mg/day oral in divided doses

Beriberi

10-25 mg IV/IM qDay (if critically ill) or 10-50 mg/dose oral qDay for at least 2 weeks, THEN

5-10 mg/day PO for one month

Duration dependent on the persistence of symptoms

• Geriatrics:

The powerful antioxidant vitamin B1 has long been believed to provide some amount of protection against the oxidative damage that contributes to the pathophysiology of Alzheimer's disease as well as general cognitive loss with ageing.

• Lactating mothers:

Vitamin B1 is a normal human milk component and a key milk antioxidant.

There is no sufficient scientific evidence traceable regarding the use and safety of Vitamin B1 for use in special populations.

Dosage Adjustment in Kidney Impairment

60-100 mg/day supplement recommended for CKD patients (dialysis and non-dialysis).

2 g/day of intravenous Vitamin B1 may be essential to achieve normal plasma concentrations during renal replacement therapy (RRT).

Current recommendations for maintaining haemodialysis patients advise supplementation

with ascorbic acid 75–90 mg daily during dialysis.

The use of Vitamin B1 should be cautiously administered in patients with renal impairment as it has been reported to cause haemolysis.

Dosage Adjustment in Hepatic Impairment

There are no specific dosage adjustments provided.

Dosage Adjustment in Adult Patients

Beriberi

IM: 5-30 mg three times daily (if critically ill); then 5-30 mg three times a day for a month.

The duration of therapy depends on the persistence of symptoms.

Wernicke Encephalopathy

100 mg IV; then 50-100 mg/day IM or IV until consuming a regular balanced diet.

Thiamin Deficiency

1 tablet or capsule/day

The need for thiamin increases when the carbohydrate content of the diet is high.

Biochemistry profile of Vitamin B1

Thiamin consists of pyrimidine and thiazole rings that are linked by a methylene bridge.

Thiamin circulates via the portal circulation, passing in plasma either free, bound to albumin, or as thiamin monophosphate to the liver, where it is phosphorylated to its TDP coenzyme form (80% total body thiamin), which is also its highest active state. Alcohol inhibits this conversion or activation, while magnesium serves as a cofactor. Thiamin enters the brain via the blood-brain barrier transporter and cerebrospinal fluid (CSF). The kidneys are mainly responsible for excreting thiamin. Skeletal muscle, the heart, the liver, the kidneys, the brain, and other organs contain large amounts of thiamin.

Kinetic profile:

• Absorption: Thiamin is a water-soluble vitamin absorbed into the blood from the gastrointestinal tract, specifically from the small intestine, through active transport at nutritional doses and passive diffusion at pharmacologic doses.
• Distribution: Vitamin B1 is highly distributed to the heart, brain, kidney
• Metabolism: The active coenzyme, thiamin diphosphate, is produced by tissues after they uptake free thiamin and thiamin monophosphate. Thiamin triphosphate, specific to the nervous system, is also produced by tissues.
• Excretion: Free thiamin is eliminated in the urine, increasing with diuresis, and considerable amounts may also be lost in sweating.

1. Braun L, Cohen M. October 1, 2014.Herbs and Natural Supplements; 4^th Edition Vol-2. Australia. Elsevier.
2. https://www.ncbi.nlm.nih.gov/books/NBK482360/
3. https://ods.od.nih.gov/factsheets/Thiamin-Consumer/
4. https://pubmed.ncbi.nlm.nih.gov/23910704/
5. https://pubmed.ncbi.nlm.nih.gov/28766407/#
6. https://www.fssai.gov.in/upload/advisories/2021/07/60f1798019f94Direction_RDA_16_07_2021.pdf