Do Vitamin D and calcium carbonate interact with Azithromycin, Levofloxacin, Amoxicillin/Clavulanate, Cefixime, and Acetaminophen?

Vitamin D and Calcium Interactions with Antibiotics and Paracetamol

Calcium carbonate can significantly reduce the absorption of levofloxacin, but vitamin D 60,000 IU does not have clinically significant interactions with any of the mentioned medications. 1, 2

Calcium Carbonate Interactions

Levofloxacin

• Major interaction: Calcium carbonate forms chelates with levofloxacin in the gastrointestinal tract, substantially reducing antibiotic absorption
• Separate administration by at least 2 hours before or 6 hours after taking calcium carbonate
• This interaction can lead to treatment failure due to subtherapeutic antibiotic levels 2

Azithromycin

• No significant interaction with calcium carbonate
• The American Thoracic Society/CDC guidelines specifically note: "Azithromycin has no significant interaction with rifamycins" and by extension, does not have clinically significant interactions with calcium supplements 1

Amoxicillin/Clavulanate (Amoxyclav)

• No clinically significant interaction with calcium carbonate
• Can be safely administered together 1

Cefixime

• No documented significant interaction with calcium carbonate
• Cephalosporins generally do not form chelates with calcium like fluoroquinolones do 1

Paracetamol (Acetaminophen)

• No clinically significant interaction with calcium carbonate
• Can be safely administered together

Vitamin D Interactions

• Vitamin D (even at high doses of 60,000 IU) does not have clinically significant interactions with:

  • Azithromycin
  • Levofloxacin
  • Amoxicillin/Clavulanate
  • Cefixime
  • Paracetamol

• In fact, some research suggests vitamin D supplementation may have beneficial effects on immune function and potentially reduce antibiotic use, particularly in older adults 3

Clinical Recommendations

1. For levofloxacin: Separate administration from calcium carbonate by at least 2 hours before or 6 hours after taking calcium

2. For all other medications: No timing adjustments needed between calcium carbonate, vitamin D, and:

   • Azithromycin
   • Amoxicillin/Clavulanate
   • Cefixime
   • Paracetamol

3. Monitoring: If taking levofloxacin with calcium supplements, monitor for signs of reduced antibiotic efficacy (persistent symptoms, lack of clinical improvement)

Common Pitfalls to Avoid

• Don't confuse fluoroquinolones with macrolides: While calcium affects levofloxacin absorption, it does not significantly affect azithromycin

• Don't assume all antibiotics interact with calcium: Only certain classes (tetracyclines, fluoroquinolones) have clinically significant interactions with calcium

• Don't overlook timing: The key to managing the levofloxacin-calcium interaction is appropriate separation of administration times

• Don't confuse vitamin D with calcium: Vitamin D itself doesn't have the same chelation properties as calcium and doesn't significantly interact with these medications