π₯ Micronutrient RDA Checker
Your intake versus NIH daily requirements.
For informational purposes only, not medical advice. Consult a healthcare professional.
Recommended Dietary Allowances are the NIH's daily intake targets covering 97 to 98% of healthy people. This checker compares your estimated daily intake of 8 key micronutrients against the RDA for your age and sex: vitamin D, vitamin C, B12, folate, calcium, iron, magnesium, and zinc. It flags anything under 75% of RDA as a gap worth closing with food first.
Enter your age, sex, and approximate daily intake of each nutrient from food plus supplements. Read the percent-of-RDA for each and the short list of gaps. Food sources beat pills for most gaps: the checker names the pattern, your plate does the fixing.
How to Use This Calculator
Estimate daily intake for each nutrient: food labels, a few days of food tracking, plus supplements. Enter age and sex for the right RDA values. Read each percent of RDA. For gaps, add food sources first (details below) and recheck in a few weeks rather than immediately buying eight bottles.
Estimate daily intake per nutrient from food plus supplements.
Enter age and sex.
Read each nutrient as percent of RDA.
Close gaps with food sources first, then recheck.
RDA Values Used
Flag gaps under 75%
RDA values come from the NIH Office of Dietary Supplements: vitamin D 15 mcg, vitamin C 90/75 mg, B12 2.4 mcg, folate 400 mcg, calcium 1,000 mg (1,200 over 50), iron 8 mg (18 for premenopausal women), magnesium 400/310 mg, zinc 11/8 mg. RDAs assume healthy people and average absorption; illness, medications, and very low calorie diets raise needs. The 75% flag is a practical gap threshold, not a deficiency diagnosis: true deficiency needs labs and symptoms, not just a low intake estimate.
Worked Example
A 35-year-old man eating 10 mcg D, 80 mg C, and so on: 1 nutrients below 75%, with the short list reading "Lowest: Vitamin D". Vitamin D at 67% and calcium at 80% are the typical gaps: indoor life and light dairy intake. A woman of childbearing age with the same diet would add iron to the short list, since her RDA is 18 mg, not 8.
Closing the Common Gaps
Vitamin D: fatty fish, fortified milk, sensible sun; supplements when levels are low. Calcium: dairy, fortified alternatives, leafy greens. Iron: red meat, lentils, and vitamin C alongside plant iron for absorption. Magnesium: nuts, whole grains, legumes. Zinc: meat, shellfish, chickpeas. B12: animal foods only in meaningful amounts, so vegans need fortified foods or a supplement. Folate: leafy greens, legumes, fortified grains (critical pre-conception). Vitamin C: citrus, peppers, berries; needs are modest and easily met.
| Nutrient | Men | Women |
|---|---|---|
| Vitamin D | 15 mcg | 15 mcg |
| Vitamin C | 90 mg | 75 mg |
| Vitamin B12 | 2.4 mcg | 2.4 mcg |
| Folate | 400 mcg | 400 mcg |
| Calcium | 1,000 mg | 1,000 mg |
| Iron | 8 mg | 18 mg (<51) |
| Magnesium | 400 mg | 310 mg |
| Zinc | 11 mg | 8 mg |
Intake Estimates Are Rough
Food tracking misestimates intake by 20% or more, and RDAs are population targets, not personal prescriptions. Do not megadose to hit 100% on everything: fat-soluble vitamins and minerals like iron and zinc cause harm in excess. Persistent fatigue, numbness, or other deficiency symptoms deserve labs, not supplement stacking. For informational purposes only, not medical advice. Consult a healthcare professional.
Related tools: mcg to IU converter, iron deficiency checker and melatonin dosage info.
For informational purposes only, not medical advice. Consult a healthcare professional.
Frequently Asked Questions
What is RDA?
Recommended Dietary Allowance: the daily intake covering 97-98% of healthy people, set by the NIH from requirement studies.
Which vitamin deficiencies are most common?
Vitamin D, iron (in premenopausal women), and B12 (in older adults and vegans) top the list in the US.
Do I need a multivitamin?
If your diet is varied, probably not. Targeted supplements for documented gaps beat shotgun multis for most people.
Can you get too much of a vitamin?
Yes for fat-soluble A, D, E, K and minerals like iron and zinc. Water-soluble B and C are excreted, with upper limits still applying.
How accurate is food tracking for micronutrients?
Rough: expect 20%+ error from label rounding, varied produce content, and cooking losses. It finds patterns, not precise intakes.
Do vegans need B12?
Yes, reliably: meaningful B12 comes only from animal foods, so fortified foods or a supplement are non-negotiable.
Why do women need more iron?
Menstrual losses. The RDA is 18 mg for premenopausal women versus 8 mg for men and postmenopausal women.
Does cooking destroy vitamins?
Heat and water reduce vitamin C and some B vitamins; minerals mostly survive. Steaming and quick cooking preserve more.
Can I be deficient in one vitamin but fine in others?
Absolutely, and it is the usual pattern. Deficiencies follow diet and life stage: a vegan may lack B12 while vitamin C is fine; someone who avoids sun may lack D while iron is normal. That is why this checker scores each nutrient separately instead of giving one blended grade. Fix the specific gap rather than overhauling everything.
Do multivitamins make tracking intake pointless?
Not pointless, but it changes the math. A daily multi covers the baseline for most nutrients at roughly 100 percent of Daily Value, so diet gaps matter less. It does not cover everything (usually light on calcium, magnesium, and vitamin D), and more is not better: fat-soluble vitamins accumulate, so stacking a multi on an already rich diet can overshoot.