Dietary Reference Intakes

Recommended Dietary Allowance (RDA) or Adequate Intake (AI), and the Tolerable Upper Intake Level (UL), per day for healthy people by life stage.

Females 31 to 50 years

NutrientRDA or AI per dayUpper limit (UL)Source
ProteinRDA or AI46 g RDAULNot determinedNASEM 2005Adult RDA is 0.8 g/kg/day; pregnancy and lactation 1.1 g/kg/day. Clinical needs in illness are set separately (protein needs calculator).
Total fiberRDA or AI25 g AIULNot determinedNASEM 2005Based on 14 g per 1,000 kcal.
Total waterRDA or AI2.7 L AIULNot determinedNASEM 2005Total water from beverages and food. Clinical fluid needs are set separately (fluid needs calculator).
Vitamin ARDA or AI700 mcg RAE RDAUL3,000 mcg RAENASEM 2001 · ODS fact sheetUL is for preformed vitamin A (retinol) only.
Vitamin CRDA or AI75 mg RDAUL2,000 mgNASEM 2000 · ODS fact sheetPeople who smoke need 35 mg/day more than nonsmokers.
Vitamin DRDA or AI15 mcg (600 IU) RDAUL100 mcg (4,000 IU)NASEM 2011 · ODS fact sheet
Vitamin ERDA or AI15 mg alpha-tocopherol RDAUL1,000 mg alpha-tocopherolNASEM 2000 · ODS fact sheetUL applies to supplemental alpha-tocopherol.
Vitamin KRDA or AI90 mcg AIULNot determinedNASEM 2001 · ODS fact sheetOn warfarin, a consistent weekly intake matters more than the amount (vitamin K food guide).
ThiaminRDA or AI1.1 mg RDAULNot determinedNASEM 1998 · ODS fact sheet
RiboflavinRDA or AI1.1 mg RDAULNot determinedNASEM 1998 · ODS fact sheet
NiacinRDA or AI14 mg NE RDAUL35 mg NENASEM 1998 · ODS fact sheetUL applies to supplements and fortified foods. Infant AI 0 to 6 months is preformed niacin (mg).
Vitamin B6RDA or AI1.3 mg RDAUL100 mgNASEM 1998 · ODS fact sheet
FolateRDA or AI400 mcg DFE RDAUL1,000 mcgNASEM 1998 · ODS fact sheetUL applies to folic acid from supplements and fortified foods (mcg), not food folate. 1 mcg DFE = 1 mcg food folate = 0.6 mcg folic acid from fortified food or with food.
Vitamin B12RDA or AI2.4 mcg RDAULNot determinedNASEM 1998 · ODS fact sheetAdults over 50 are advised to get most B12 from fortified foods or supplements. Metformin and acid suppressants can lower B12 (drug–nutrient planner).
CholineRDA or AI425 mg AIUL3,500 mgNASEM 1998 · ODS fact sheet
CalciumRDA or AI1,000 mg RDAUL2,500 mgNASEM 2011 · ODS fact sheet
IronRDA or AI18 mg RDAUL45 mgNASEM 2001 · ODS fact sheetVegetarians may need 1.8 times the RDA because nonheme iron is less bioavailable.
MagnesiumRDA or AI320 mg RDAUL350 mgNASEM 1997 · ODS fact sheetUL applies to magnesium from supplements and medications only, not food.
PhosphorusRDA or AI700 mg RDAUL4,000 mgNASEM 1997 · ODS fact sheet
ZincRDA or AI8 mg RDAUL40 mgNASEM 2001 · ODS fact sheet
IodineRDA or AI150 mcg RDAUL1,100 mcgNASEM 2001 · ODS fact sheet
SeleniumRDA or AI55 mcg RDAUL400 mcgNASEM 2000 · ODS fact sheet
PotassiumRDA or AI2,600 mg AIULNot determinedNASEM 2019 · ODS fact sheetAIs are for healthy people. In kidney disease or with drugs that raise potassium (ACE inhibitors, ARBs, spironolactone), intake is individualized.
SodiumRDA or AI1,500 mg AIUL2,300 mg CDRRNASEM 2019No UL is set for sodium. The Chronic Disease Risk Reduction (CDRR) intake is the level above which reducing intake is expected to lower chronic disease risk.

RDA: average daily intake that meets the needs of nearly all (97 to 98%) healthy people. AI: set when evidence is not enough for an RDA; intake assumed to be adequate. UL: highest daily intake unlikely to cause harm; "not determined" does not mean large amounts are safe. CDRR: Chronic Disease Risk Reduction intake for sodium.

DRIs are for healthy people. Needs in illness (kidney disease, critical illness, malabsorption) and drug–nutrient effects are assessed separately: see the drug–nutrient planner and the protein, energy and fluid calculators.

Sources: National Academies of Sciences, Engineering, and Medicine (formerly Institute of Medicine) Dietary Reference Intakes reports, as reproduced in the NIH Office of Dietary Supplements Health Professional fact sheets (public domain). Each row links its report and fact sheet.

For licensed clinicians. Use with clinical judgment.