What is the equivalent of 400 milligrams (mg) of vitamin E acetate in International Units (IU)?

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Vitamin E Acetate 400 mg Conversion to IU

400 mg of vitamin E acetate equals 889 IU of vitamin E.

Conversion Factors for Vitamin E

The conversion between milligrams (mg) and International Units (IU) for vitamin E depends on the form of vitamin E being used:

  • For natural vitamin E (d-α-tocopherol): 1 IU = 0.67 mg 1
  • For synthetic vitamin E (dl-α-tocopherol): 1 IU = 0.45 mg 1
  • For vitamin E acetate (dl-α-tocopheryl acetate): 1 IU = 0.45 mg 1

Calculation for Vitamin E Acetate

To convert 400 mg of vitamin E acetate to IU:

  • 400 mg ÷ 0.45 mg/IU = 889 IU 1

Clinical Considerations for Vitamin E Dosing

Recommended Daily Intake

  • The Recommended Dietary Allowance (RDA) for adults is 15 mg/day (approximately 22 IU/day) 1
  • For preterm infants receiving parenteral nutrition: 2.8-3.5 mg/kg/day, not exceeding 11 mg/day 2
  • For children below 11 years receiving parenteral nutrition: ≤11 mg/day 2

Safety Considerations

  • Doses ≤400 IU/day (180 mg/day) appear to have no effect on all-cause mortality 2
  • High-dosage vitamin E supplementation (≥400 IU/day) may potentially increase all-cause mortality and should be used with caution 3
  • The Tolerable Upper Limit for vitamin E is 1000 mg/day (approximately 1500 IU/day) of any form of supplementary α-tocopherol 2

Bioavailability Considerations

  • The bioavailability ratio of natural to synthetic vitamin E is approximately 1.36:1 4
  • In patients with normal lipid absorption, fat-soluble forms of vitamin E are generally preferable for therapeutic and prophylactic uses 5
  • In cases of cholestasis and other forms of lipid malabsorption, water-miscible forms of vitamin E may be more appropriate 5

Assessment of Vitamin E Status

  • For accurate assessment of vitamin E status, the ratio between serum vitamin E and total serum lipids should be used rather than absolute serum levels 2, 1
  • Deficiency is indicated by a serum vitamin E/total lipid ratio <0.8 mg/g of total lipids 1

Special Populations

  • Older adults may benefit from vitamin E supplementation at doses of approximately 200 IU/day (90 mg/day) to improve immune function 2
  • Patients with cystic fibrosis can be efficiently supplemented with 400 IU/day of various vitamin E preparations to achieve normal plasma values 6
  • Smokers may handle vitamin E differently than non-smokers, potentially affecting bioavailability 4

Remember that vitamin E is a fat-soluble vitamin, and excessive supplementation can lead to accumulation in the body. Always consider the total vitamin E intake from all sources, including diet, multivitamins, and specific supplements.

References

Guideline

Vitamin E Conversion and Recommended Dosage

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Vitamin E bioavailability in humans.

Journal of plant physiology, 2005

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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