How many substances have a recommended daily intake for a healthy adult?

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How Many Substances Have a Recommended Daily Intake

Based on the Institute of Medicine's Dietary Reference Intakes (DRIs), at least 15 vitamins and minerals have established Recommended Dietary Allowances (RDAs) or Adequate Intakes (AIs) for healthy adults. 1

Substances with Established RDAs

The following vitamins and minerals have specific RDAs defined for healthy adults:

Vitamins with RDAs

  • Vitamin A: 700 µg/day for women, 900 µg/day for men 1
  • Vitamin B6: 1.3 mg/day 1
  • Vitamin B12: 2.4 µg/day 1
  • Folic acid: 400 µg/day of dietary folate equivalents 1
  • Niacin: 14 mg/day niacin equivalents for women, 16 mg/day for men 1
  • Riboflavin: 1.1 mg/day for women, 1.3 mg/day for men 1
  • Thiamin: 1.1 mg/day for women, 1.3 mg/day for men 1
  • Vitamin C: 75 mg/day for women, 90 mg/day for men 1
  • Vitamin E: 15 mg/day α-tocopherol 1
  • Vitamin K: 90 mcg/day for adults 1

Minerals with RDAs

  • Calcium: 1,000 mg/day for adults ≤50 years, 1,200 mg/day for adults >50 years 1
  • Iron: 8 mg/day for men and postmenopausal women, 18 mg/day for premenopausal women 1
  • Magnesium: 320 mg/day for women, 420 mg/day for men 1
  • Selenium: 55 µg/day 1
  • Zinc: 8 mg/day for women, 11 mg/day for men 1

Substances with Adequate Intakes (AIs) Only

Several additional substances have Adequate Intakes established but insufficient data to set formal RDAs:

  • Chromium: 25 µg/day for women, 35 µg/day for men 1
  • Biotin: 40 mg/day for adults 1
  • Fluoride: 0.05 mg/kg/day 1
  • Manganese: 3 mg/day 1
  • Molybdenum: 65 mg/day 1
  • Pantothenic acid: 7 mg/day for lactating women (similar for adults) 1

Substances Without Established Requirements

Notably, some substances do not have established DRIs:

  • Vanadium: Insufficient data to set RDA or adequate intake 1
  • Chromium: The European Food Safety Authority concluded that no average requirement or population reference intake can be defined, and there is no evidence of beneficial effects in healthy subjects 1

Important Caveats

The total count of substances with recommended intakes is approximately 20-25 vitamins and minerals for healthy adults. 1 This number increases when considering:

  • Additional nutrients with established requirements during pregnancy and lactation 1
  • Macronutrients (carbohydrates, proteins, fats) which also have DRIs but were not the focus of the vitamin/mineral tables 1
  • Sodium, which has a WHO recommendation of <2 g/day 1

The DRIs represent intake levels sufficient to meet the nutrient requirements of 97-98% of healthy individuals within specific age, sex, and life stage groups. 1 These recommendations assume adequate dietary intake and do not necessarily support routine supplementation in healthy adults without underlying deficiencies. 1

References

1
Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

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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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