Use this estimator to compare your daily vitamin intake with age, sex, and life-stage targets. It models absorbed intake, average supplement use across the week, percent of target reached, and remaining space before a standard upper limit when one exists.
Calculator form
Enter food intake and supplement intake in the same unit shown for your chosen vitamin.
Example data table
These sample rows show how the estimator behaves with different profiles and vitamins.
| Profile | Vitamin | Target | Total Intake | Absorbed | Gap | Status |
|---|---|---|---|---|---|---|
| Male, 34, smoker | Vitamin C | 125 mg | 130 mg | 117 mg | 8 mg | Within planning range |
| Female, 45 | Vitamin D | 15 mcg | 24.86 mcg | 22.37 mcg | 0 mcg | Above target, below UL |
| Female, 29, pregnant | Folate | 600 mcg DFE | 750 mcg DFE | 637.5 mcg DFE | 0 mcg DFE | Within target zone |
| Female, 67 | Vitamin B12 | 2.4 mcg | 4 mcg | 3.8 mcg | 0 mcg | Above target, no UL used |
Formula used
1. Reference target
Target = age and sex reference value for the selected vitamin.
Pregnancy, lactation, and smoking can change the target.
2. Effective supplement intake
Effective Supplement = Supplement Amount × (Supplement Days ÷ 7)
3. Total modeled intake
Total Intake = Dietary Intake + Effective Supplement
4. Absorbed estimate
Absorbed Intake = Total Intake × (Absorption % ÷ 100)
5. Gap and status
Gap = max(Target − Absorbed Intake, 0)
Percent Met = (Absorbed Intake ÷ Target) × 100
6. Safety check
Remaining Safe Room = Upper Limit − Total Intake, when a standard upper limit exists.
How to use this calculator
- Choose the vitamin you want to evaluate.
- Enter age and sex so the reference target can adjust correctly.
- Switch on pregnancy, lactation, or smoking when those apply.
- Type your estimated dietary intake in the unit used by that vitamin.
- Add the supplement amount you take on a day you use it.
- Enter how many days each week you actually take the supplement.
- Set an absorption percentage if you want a conservative or optimistic model.
- Press calculate and review the result, graph, gap, and export files.
Frequently asked questions
1. What does this vitamin calculator estimate?
It estimates a daily vitamin target, your modeled total intake, absorbed intake, target gap, and remaining room before a standard upper limit when one is available.
2. Why does absorbed intake differ from total intake?
Total intake adds food and average supplement intake. Absorbed intake then applies your chosen absorption percentage, which creates a planning estimate instead of assuming every unit consumed is fully used.
3. Does the chart diagnose deficiency?
No. The chart is a nutrition planning view. It cannot diagnose deficiency, toxicity, or disease. Lab testing, symptoms, medications, and clinical history still matter.
4. Why can smoking change vitamin C targets?
Smoking increases oxidative stress, so vitamin C needs are often set higher for smokers. This calculator raises the vitamin C target when the smoker box is selected.
5. Why do some vitamins show no upper limit here?
Some vitamins, such as vitamin K or vitamin B12, do not use a standard upper limit in this model. The calculator then focuses on target progress instead of a safety ceiling.
6. Can I use this during pregnancy or lactation?
Yes, for planning only. Pregnancy and lactation change several targets, especially folate and vitamin A. Personalized care still matters, so confirm supplements with a clinician.
7. How often should I recalculate?
Recalculate when your supplement routine, diet pattern, age band, or life stage changes. A small habit shift can meaningfully change average weekly intake.
8. What should I enter for supplement days each week?
Enter how many days, from zero to seven, you usually take the supplement. The calculator converts that routine into an average daily contribution automatically.