There are 13 essential vitamins and 12 essential minerals your body needs to function. The Institute of Medicine and NIH Office of Dietary Supplements publish Recommended Dietary Allowances (RDA) for each, varying by age, sex, and life stage. Our vitamin and mineral calculator surfaces the right RDA values for your situation in one place — vitamins A, C, D, E, K, all 8 B vitamins, plus calcium, iron, magnesium, phosphorus, potassium, sodium, zinc, copper, selenium, iodine, manganese, and chromium. It also adjusts for pregnancy and lactation where the requirements differ.
Provide your age and biological sex.
Toggle if pregnant or lactating for adjusted values.
See daily recommendations for all 13 vitamins and 12 minerals.
RDA values are set to meet the needs of 97-98% of healthy individuals in a given group. Where data is insufficient, the IOM uses Adequate Intake (AI) instead. The Tolerable Upper Intake Level (UL) is the maximum daily amount unlikely to cause harm. Pregnancy and lactation increase requirements for several nutrients (folate, iron, B12, calcium, iodine) — the calculator applies the relevant adjustments.
RDA = NIH/IOM published value for your age + sex + life stage
RDA values cover 97-98% of healthy people — most don't need supplements if eating a varied diet
Common shortfalls in US diets: vitamin D, calcium, magnesium, potassium, fiber
Iron requirements jump from 8 mg (men) to 18 mg (premenopausal women) due to menstrual losses
Pregnancy increases folate, iron, and iodine requirements substantially
Vitamin D is hard to get from food alone — sunlight or supplements often needed
B12 absorption decreases with age — adults over 50 should consider supplementation
Don't exceed Tolerable Upper Intake Levels (UL) — too much of some vitamins can be harmful
Vitamins are essential organic compounds that the body needs in small amounts for hundreds of metabolic processes, from energy production and immune function to bone health and DNA repair. The National Institutes of Health (NIH) publishes Recommended Dietary Allowances (RDAs) that vary significantly by age, sex, and life stage — for example, adult men need 90 mg of vitamin C daily while women need 75 mg, but pregnant women require 85 mg and breastfeeding women need 120 mg. Vitamin D requirements have been a particular focus: the RDA is 600 IU (15 mcg) for adults under 70 and 800 IU (20 mcg) for those over 70, yet surveys show that approximately 42% of US adults are vitamin D deficient. Fat-soluble vitamins (A, D, E, K) are stored in body tissue and can accumulate to toxic levels — the tolerable upper intake for vitamin A is 3,000 mcg RAE, beyond which liver damage risk increases. Water-soluble vitamins (B-complex and C) are excreted in urine, making toxicity rare but also requiring more consistent daily intake. Individual needs diverge further based on diet (vegans need supplemental B12), medical conditions, medications, and lifestyle factors like smoking (which increases vitamin C requirements by 35 mg/day).
Nutrient requirements change dramatically across the lifespan.
Using a single 'adult' RDA misses these important differences.
Food is almost always preferable to supplements because it provides nutrients in their natural matrix with co-factors and fiber.
Supplements have a place:
Beyond these specific cases, taking high-dose supplements 'just in case' has little evidence of benefit and some evidence of harm.
Recommended vitamin intakes come from the Dietary Reference Intakes (DRIs) set by the National Academies (formerly the Institute of Medicine) and summarized by the NIH Office of Dietary Supplements.
They vary by nutrient, age, sex, and life stage — for example, adults need about:
This calculator matches DRIs to your profile so targets are personalized, not generic.
The DRIs include several values:
The NIH Office of Dietary Supplements stresses that more is not better — exceeding the UL, especially for fat-soluble vitamins, can be toxic.
Aim for the RDA/AI, not the maximum.
Vitamins A, D, E, and K are fat-soluble — stored in body fat and the liver, so excess can accumulate to toxic levels.
Vitamins C and the B-complex are water-soluble — not stored much, with surplus excreted in urine, so they need more regular replenishment but are harder to overdose from food.
Per the NIH, this distinction explains why fat-soluble vitamin supplements carry more toxicity risk and why water-soluble ones need daily intake.
Each vitamin has distinct roles:
The NIH Office of Dietary Supplements maintains detailed fact sheets for each.
A varied diet of fruits, vegetables, whole grains, and proteins supplies most people's full range.
Requirements shift across life.
This is why the calculator asks about age, sex, and pregnancy/lactation — the National Academies set distinct reference values for each life stage.
Deficiencies produce recognizable signs:
The NIH notes deficiencies are more common in restrictive diets, malabsorption conditions, pregnancy, and older age. Symptoms are nonspecific, so blood tests confirm true deficiency.
Persistent fatigue or unusual symptoms warrant a clinician's evaluation rather than self-diagnosis and high-dose supplements.
Yes — especially fat-soluble vitamins and some minerals, where exceeding the Tolerable Upper Intake Level can cause harm (e.g., vitamin A toxicity, excess vitamin D raising blood calcium). The NIH Office of Dietary Supplements documents these risks.
Megadoses rarely help healthy people and can interact with medications.
Unless a clinician diagnoses a deficiency, staying near the RDA — mostly from food — is safer than high-dose supplementation.
Nutrition authorities including the Dietary Guidelines advocate a 'food first' approach: whole foods provide vitamins alongside fiber, minerals, and beneficial compounds that isolated supplements lack.
Supplements help fill genuine gaps — vitamin D in low-sun climates, B12 for vegans, folate in pregnancy — but are not a substitute for a varied diet.
Choose supplements to target specific, identified needs rather than as blanket insurance.
Common mistakes include:
Aim for the RDA/AI mostly from food, respect upper limits, confirm deficiencies with a clinician, and target supplements to real gaps like vitamin D, B12, or prenatal folate rather than taking everything.
Data sourced from trusted institutions
All formulas verified against official standards.