Can B vitamin deficiencies cause palpitations?

B Vitamin Deficiencies and Palpitations

Yes, B vitamin deficiencies, particularly vitamin B12 deficiency, can cause palpitations due to their effects on cardiac function and the nervous system. 1

Relationship Between B Vitamins and Cardiovascular Function

• Vitamin B12 deficiency specifically has been associated with cardiac autonomic dysfunction, heart rate variability, and endothelial dysfunction, which can manifest as palpitations 1
• Low vitamin B12 levels are significantly correlated with electrocardiographic repolarization disorders, which are indicators of arrhythmogenic predisposition even in otherwise healthy individuals 1
• Research has demonstrated that individuals with low vitamin B12 levels (<253 pg/ml) have significantly higher QT and QTc dispersions, Tp-e interval, and Tp-e/QT ratios compared to those with normal or high vitamin B12 levels 1

Specific B Vitamin Deficiencies and Cardiac Effects

Vitamin B12 (Cobalamin)

• Vitamin B12 deficiency can lead to:
  • Cardiac autonomic dysfunction 1
  • Increased arrhythmogenic susceptibility 1
  • Palpitations as a direct symptom 1
  • Anemia, which can indirectly cause palpitations through compensatory tachycardia 2

Thiamin (Vitamin B1)

• Thiamin deficiency has been characterized by:
  • Cardiovascular manifestations including tachycardia and palpitations 3
  • Wet beriberi (cardiac form) which presents with high-output heart failure and palpitations 3
  • Neural and neuromuscular compromise that can affect cardiac function 3

Other B Vitamins

• Niacin (B3) deficiency has been associated with cardiovascular effects, though supplementation might potentially increase mortality 4
• Vitamin B6 deficiency has been linked to increased risk of cardiovascular disease, though the exact mechanisms remain under investigation 5

Diagnostic Considerations

• When evaluating patients with unexplained palpitations, consider measuring serum B12 levels, especially if other symptoms of deficiency are present 1
• Metabolic B12 deficiency (serum B12 below 258 pmol/L with elevated plasma total homocysteine or methylmalonic acid) is frequently missed because normal range serum B12 is often accepted as ruling out deficiency 3
• In patients with palpitations and suspected B vitamin deficiencies, ECG measurements should be performed to evaluate QT intervals and other repolarization parameters 1

Treatment Approach

• For confirmed vitamin B12 deficiency with palpitations:
  • Supplementation with methylcobalamin or hydroxycobalamin forms is preferred over cyanocobalamin, especially in patients with renal impairment 6
  • Initial treatment may require daily supplementation followed by weekly and then monthly maintenance doses 2
• For thiamin deficiency:
  • Prompt supplementation is necessary, especially before administering glucose, which can worsen deficiency 3
• Regular monitoring of cardiac parameters during supplementation is recommended to assess improvement 1

Important Caveats

• Palpitations have multiple potential causes beyond B vitamin deficiencies, requiring comprehensive evaluation 1
• High-dose B vitamin supplementation is not recommended for general cardiovascular health and may be harmful in certain populations 3, 4
• B vitamin supplementation for homocysteine lowering is not recommended for prevention of cardiovascular events in patients with peripheral arterial disease 3
• Patients with renal failure may have elevated B12 levels despite functional deficiency, requiring careful interpretation of laboratory values 6