Intake recommendations

Last update: 23 August 2021

This is a summary of dietary micronutrient recommendations, their basis and strength. Only references for non-elderly, non-pregnant adults, being the best researched demographic, are considered. Recommendation strength and commentary is my opinion, primarily on the basis of whether there is sufficient evidence to put a number to a nutrient, and say you need to eat this much.

Retinol (vitamin A)Clinical symptom thresholds, storage ability, absorption efficiencyStrong1
Vitamin KIntake observationWeak1
ChromiumDesigned diet analysisVery weakThis is guesswork1
CopperSaturation indicatorsWeak1
IodineStatus indicatorsWeak1
IronClinical symptom thresholds, balance indicators, absorption efficiencyStrong1
ManganeseIntake observationWeak1
MolybdenumBalance indicatorsWeak1
ZincBalance calculationWeak1
CalciumBalance indicatorsWeak2, 4
Vitamin DClinical symptoms thresholds, status indicatorsModerateStatistical error yields underestimate2, 3, 4, 7
PhosphorusIntake observationWeak4
MagnesiumBalance indicatorsWeak4
FluorideIntake observationWeak4
Vitamin CSaturation indicatorsWeak5
Vitamin EOxidative damage markers, intake observationModerate5
SeleniumClinical symptom thresholds, saturation indicatorsStrong5
Thiamin (vitamin B1)Clinical symptom thresholds, biochemistry markersStrong6
Riboflavin (vitamin B2)Clinical symptom thresholds, saturation indicatorsStrong6
Niacin (vitamin B3)Clinical symptom thresholds, saturation indicatorsStrong6
Vitamin B6Clinical symptom thresholds, status indicatorsModerateConfounded evidence6
Folate (vitamin B9)Status indicatorsWeak6
Vitamin B12Status indicatorsWeak6
Pantothenic Acid (vitamin B5)Intake observationWeak6
Biotin (vitamin B7)Human milk extrapolationWeak6
CholineStatus indicatorsWeak6
PotassiumPopulation intakesWeak8
SodiumBalance indicators, symptom-free clinical observationsModerate8


  1. Institute of Medicine (US) Panel on Micronutrients. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington (DC): National Academies Press (US); 2001. Available from: doi: 10.17226/10026
  2. Institute of Medicine (US) Committee to Review Dietary Reference Intakes for Vitamin D and Calcium; Ross AC, Taylor CL, Yaktine AL, et al., editors. Dietary Reference Intakes for Calcium and Vitamin D. Washington (DC): National Academies Press (US); 2011. Available from: doi: 10.17226/13050
  3. Veugelers PJ, Ekwaru JP. A statistical error in the estimation of the recommended dietary allowance for vitamin D. Nutrients. 2014;6(10):4472–4475. Published 2014 Oct 20. doi:10.3390/nu6104472
  4. Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Washington (DC): National Academies Press (US); 1997. Available from: doi: 10.17226/5776
  5. Institute of Medicine (US) Panel on Dietary Antioxidants and Related Compounds. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington (DC): National Academies Press (US); 2000. Available from: doi: 10.17226/9810
  6. Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes and its Panel on Folate, Other B Vitamins, and Choline. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington (DC): National Academies Press (US); 1998. Available from: doi: 10.17226/6015
  7. Kevin D Cashman, Tom R Hill, Alice J Lucey, Nicola Taylor, Kelly M Seamans, Siobhan Muldowney, Anthony P FitzGerald, Albert Flynn, Maria S Barnes, Geraldine Horigan, Maxine P Bonham, Emeir M Duffy, JJ Strain, Julie MW Wallace, Mairead Kiely, Estimation of the dietary requirement for vitamin D in healthy adults, The American Journal of Clinical Nutrition, Volume 88, Issue 6, December 2008, Pages 1535–1542,
  8. National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Food and Nutrition Board; Committee to Review the Dietary Reference Intakes for Sodium and Potassium; Oria M, Harrison M, Stallings VA, editors. Dietary Reference Intakes for Sodium and Potassium. Washington (DC): National Academies Press (US); 2019 Mar 5. Available from: doi: 10.17226/25353