Clinical medicine profile
Vitamin B1 (Thiamine)
Vitamin / mineral / nutritional supplement
- Route
- ORAL / IM / IV (selected)
- Schedule
- POM
- ATC
- Not assigned
- PPB status
- registered
This profile needs source confirmation
A traceable source link is not attached to this profile. Confirm prescribing decisions against the current SmPC and Kenya STG/EML.
Safety essentials
The information most likely to change a prescribing or dispensing decision.
Contraindications
- Hypervitaminosis risk states (hypercalcaemia for vitamin D/A).
- Iron: avoid in iron overload.
- Potassium: severe hyperkalaemia / untreated Addison's.
Precautions
- Treat confirmed deficiency with monitored repletion.
- Avoid megadoses without indication.
- Iron: keep away from children (overdose lethal).
Dosing matrix
Population and organ-function guidance, shown together for faster comparison.
Mild chronic deficiency: 10-25mg daily. Severe deficiency; 200-300mg daily. Multivitamin therapy is concomitantly given.
See label paediatric section if present; otherwise use paediatric formulary — do not extrapolate adult doses.
Fat-soluble vitamins and potassium need care in advanced CKD.
- CrCl 0–120: Confirm renal dosing in product SmPC / primary label.
Vitamin A toxicity hepatic; niacin hepatotoxicity at high dose.
Use, effects & interactions
Indications
- Prophylaxis and treatment of Thiamine deficiency
- supplement in the following conditions alcoholism, burns, chronic fever, gastrectomy, haemodialysis, chronic hepatic-biliary tract disease, hepatic function disorder, hyperthyroidism, prolonged infection, prolonged stress
- treatment of maple syrup urine disease
- treatment of pyruvate carboxylase deficiency
- treatment subacute necrotizing encephalomyelopathy
- treatment of hyperalaninaemia.
Adverse effects
- GI upset (iron, high-dose vitamin C).
- Hypercalcaemia (vitamin D excess).
- Neuropathy with B6 megadoses.
- Flushing (niacin).
Drug interactions
Open multi-drug checker ↗- ||| Alcoholics often become deficient of this vitamin, perhaps because of their eating habit.
- Its deficiency causes beriberi, in which there may be high output heart failure, peripheral neuritis or encephalopathy.
- ||| Natural Sources: Lightly milled wheat, unpolished maize and rice, green vegetables, beef, liver and egg york.
Mechanism & disposition
It combines with ATP to form a coenzyme, thiamine pyrophosphate, which is necessary for carbohydrate metabolism.
Read complete mechanism
It combines with ATP to form a coenzyme, thiamine pyrophosphate, which is necessary for carbohydrate metabolism. Vitamins and minerals act as cofactors, antioxidants, structural elements or hormone precursors (e.g. vitamin D endocrine axis). Pharmacological high-dose effects differ from nutritional repletion.
Days–weeks for repletion
Depends on stores and ongoing intake
ORAL / IM / IV (selected)
depends on GI integrity, food matrix and binders (e.g. calcium/iron interactions). Fat-soluble vitamins (A,D,E,K) accumulate; water-soluble generally renally cleared.
Pregnancy, lactation & diet
Folic acid preconception/first trimester critical. Iron/folate common in ANC. Avoid excess vitamin A.
Maternal repletion often appropriate; avoid megadoses.
Brands & loaded prices
| Brand | Manufacturer | Pack | Observed price |
|---|---|---|---|
| No reviewed brand listings are linked yet. | |||
Sources & review state
Decision support only. Confirm patient-specific decisions against the current product SmPC, Kenya STG/EML, and professional judgement.