Calculator Inputs
Formula Used
- Total intake (raw) = Dietary selenium + Supplemental selenium
- Adjusted intake = Total intake (raw) × Bioavailability factor
- Gap to target = (RDA/AI target) − Adjusted intake
- Effective UL = UL − Safety buffer
- Headroom = Effective UL − Adjusted intake
How to Use This Calculator
- Enter your age and choose years or months.
- Select pregnancy or lactation status if relevant.
- Estimate selenium from diet and supplements in micrograms.
- Keep bioavailability at 1.00× unless testing sensitivity.
- Review the target, UL, and headroom after calculating.
Example Data Table
Values are illustrative averages and can vary by brand, origin, and preparation method.
| Food (typical serving) | Estimated selenium (mcg) | Notes |
|---|---|---|
| Brazil nut (1 nut) | 70 | Highly variable; can be very high. |
| Tuna, cooked (85 g) | 60 | Seafood is often selenium-rich. |
| Egg (1 large) | 15 | Useful daily source with protein. |
| Brown rice, cooked (1 cup) | 18 | Grain content varies by soil. |
| Sunflower seeds (28 g) | 19 | Also provides vitamin E and fats. |
Safety Notes
- High selenium can cause hair/nail brittleness, GI upset, and “garlic breath” odor.
- If you use supplements, keep totals comfortably below the UL unless advised by a clinician.
- Kidney disease, thyroid conditions, and certain medications may require individualized guidance.
Selenium’s Role in Health
Selenium is a trace mineral supporting antioxidant enzymes and thyroid hormone metabolism. Reference targets are stated in micrograms per day, so unit accuracy matters. This calculator adds dietary selenium and supplement label amounts to estimate total intake. It then compares your total with a life-stage target and an upper limit. The summary indicates likely low intake, target range, or potential excess. Use to review patterns before changing supplements.
Life‑Stage Intake Targets
Targets vary by age and physiology. Infants use Adequate Intake values: 15 mcg/day at 0–6 months and 20 mcg/day at 7–12 months. Children typically progress from 20 mcg/day (1–3 years) to 30 (4–8 years) and 40 (9–13 years). Teens and adults generally use 55 mcg/day. Pregnancy raises the target to 60, lactation to 70. These are daily microgram goals.
Upper Limit and Buffering
Safety is evaluated with the Tolerable Upper Intake Level (UL). Typical UL values are 45 mcg/day (0–6 months), 60 (7–12 months), 90 (1–3 years), 150 (4–8 years), 280 (9–13 years), and 400 for ages 14+. The calculator allows a safety buffer that lowers the effective UL, creating headroom and reducing risk when multiple foods and supplements overlap. Stay below the effective UL.
Estimating Dietary Selenium
Dietary selenium depends on soil content and food choice, so estimates are approximate. For planning, add typical servings: seafood and poultry often contribute tens of micrograms, eggs contribute around the mid‑teens, and grains contribute variable amounts. Some foods can dominate totals; Brazil nuts may contain very high selenium per nut depending on origin. Use the example table as a template, then refine using labels or nutrient databases when available.
Exports and Ongoing Tracking
The exports support tracking and sharing. After calculating, download CSV to store results in spreadsheets, food logs, or coaching notes. Download PDF for a snapshot you can email or bring to appointments. If your total is below target, increase food sources first and recalculate. If it approaches the effective UL, reduce supplemental selenium, then review again after routine changes. Document supplement doses and timing to keep comparisons consistent.
FAQs
1) What unit does the calculator use?
All values are shown in micrograms (mcg) per day. Check supplement labels carefully, because some brands list selenium per tablet, while others list per serving size.
2) Is the result medical advice?
No. It is an educational estimate based on reference targets and upper limits. If you have symptoms, chronic disease, pregnancy concerns, or take medications, discuss selenium intake with a clinician.
3) How can I estimate dietary selenium?
Use food labels when available, then approximate with reputable nutrient databases. Add your main selenium-rich items, and treat the total as a planning estimate because soil and sourcing cause wide variation.
4) What should I do if I exceed the upper limit?
Reduce or stop supplemental selenium first, then recalculate. Recheck any high-selenium foods you eat frequently. If you remain above the limit or feel unwell, seek professional guidance promptly.
5) Why is there a bioavailability factor?
It is a sensitivity tool. It lets you test how conclusions change if absorption or label accuracy differs from assumptions. Keep it at 1.00× for standard use unless you have a specific reason.
6) Can Brazil nuts skew my intake?
Yes. Selenium content in Brazil nuts can be extremely high and variable. Even one nut may add a large amount, so enter it cautiously and avoid stacking high-dose supplements on the same day.