Can discontinuing 1.25mg of folic acid (Vitamin B9) supplementation immediately prevent potential harm to a 6-month-old infant's liver or kidneys?

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Folic Acid Safety in a 6-Month-Old Infant

A dose of 1.25 mg folic acid daily in a 6-month-old infant is approximately 6-fold higher than the recommended daily allowance but is not known to cause liver or kidney damage at this dose, and you can discontinue it immediately without tapering. 1, 2

Safety Profile of Folic Acid in Infants

Folic acid does not cause hepatotoxicity or nephrotoxicity at standard supplementation doses in infants. The evidence regarding folic acid and organ toxicity is reassuring:

  • Liver safety: Folic acid is water-soluble and excess amounts are typically excreted in urine rather than accumulating to toxic levels. 3 The liver is the main organ for storing and metabolizing folate, but therapeutic doses do not cause liver injury in the absence of underlying liver disease. 3

  • Kidney safety: While extremely high experimental doses of folic acid (100-250 mg/kg body weight) have induced acute renal failure in animal models through oxidative stress mechanisms, these doses are 1000-fold higher than typical human supplementation. 4, 5 A 1.25 mg daily dose in an infant is nowhere near this threshold.

  • Recommended intake: Infants 6 months old require approximately 65-80 mcg (0.065-0.08 mg) of dietary folate equivalents daily. 1 Your infant received 1.25 mg (1250 mcg), which is elevated but within the range used safely in clinical practice.

Discontinuation Protocol

You can stop the folic acid immediately without any tapering schedule. 6

  • Folic acid supplementation can be discontinued abruptly without adverse effects other than potential return of any deficiency that prompted supplementation. 6

  • There is no withdrawal syndrome or rebound effect from stopping folic acid. 6

  • The water-soluble nature of folic acid means excess is rapidly cleared from the body through urine. 3

Critical Safety Consideration

The only significant concern with folic acid supplementation is that it can mask vitamin B12 deficiency while allowing neurological damage to progress. 2, 7

  • If your infant was given folic acid for anemia or any hematologic reason, ensure vitamin B12 status was checked before starting supplementation. 2, 7

  • Folic acid doses exceeding 0.4 mg daily should not be given until pernicious anemia (B12 deficiency) has been ruled out. 7

  • If B12 deficiency exists, folic acid can improve blood parameters while neurological manifestations worsen. 2, 7

Monitoring Recommendations

No specific monitoring is required after discontinuation unless the folic acid was treating a documented deficiency:

  • If the supplementation was for documented folate deficiency, recheck folate status 3 months after discontinuation. 2

  • Watch for signs of recurrent deficiency only if there was an underlying condition requiring supplementation (malabsorption, certain medications, etc.). 2

  • No liver or kidney function tests are needed as folic acid at this dose does not cause organ toxicity. 3

Why Was This Prescribed?

Understanding the original indication helps determine next steps:

  • If prescribed for neural tube defect prevention in pregnancy (maternal supplementation), this dose is appropriate for pregnant women but was likely given to the infant by error. 2

  • If prescribed for documented folate deficiency, consult the prescribing physician before discontinuation to address the underlying cause. 2

  • If prescribed alongside methotrexate or other folate antagonist medications, folic acid supplementation is medically necessary and should not be stopped without consulting the prescribing physician. 6, 1

References

Guideline

Folate Supplementation Alternatives

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

L-Methylfolate Prescription Guidelines

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Research

Folic acid induces acute renal failure (ARF) by enhancing renal prooxidant state.

Experimental and toxicologic pathology : official journal of the Gesellschaft fur Toxikologische Pathologie, 2012

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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