Selenium Intake Calculator
Score daily selenium percent and gap from foods by life stage.
What it does
Selenium supports thyroid and antioxidant defenses in tiny amounts. Fish, turkey, and eggs carry steady doses, while one Brazil nut can overshoot the day alone.
The tool above scores the day. An adult woman target is 55 mcg, so 40 mcg reads 72.7 % with 15 mcg more to find. Kids target 30 mcg, pregnancy 60 mcg, breastfeeding 70 mcg.
Fish sets the pace. Tuna and halibut add tens of micrograms per serving, turkey and eggs add smaller steady shares, and grains vary with soil.
Brazil nuts break the scale. A single nut may hold 70 to 90 mcg, so eat them by count per week, not by handful.
Ceilings matter here. The tolerable top sits near 400 mcg, so food gaps close with fish dinners, never with stacked pills.
How to use
- Pick life stage.
- Enter food selenium in mcg.
- Read target first.
- Read percent next.
- Read gap and add fish or eggs.
- Score a week, not one meal.
Formula
- stage
- Life stage setting the target.
- food
- Selenium from foods, in mcg.
Targets follow NIH ODS recommended intakes. Food mcg comes from labels or USDA FoodData entries summed for the day.
Worked example
Example: adult woman, 40 mcg from food
Defaults: adult woman eating 40 mcg. These are also the default values, so the page opens on this answer.
- Stage: adult woman, target 55 mcg.
- Food: 40 mcg from fish and grains.
- Share: 40 / 55 x 100 = 72.7 %.
- Gap: 55 - 40 = 15 mcg more.
- Tool shows 55 mcg, 72.7 %, 15 mcg more.
Reference table
| Stage | Target | Example score |
|---|---|---|
| Child | 30 mcg | 20 mcg is 66.7 % |
| Adult woman | 55 mcg | 40 mcg is 72.7 % |
| Pregnancy | 60 mcg | 50 mcg is 83.3 % |
| Breastfeeding | 70 mcg | 60 mcg is 85.7 % |
Limits
- Intake scoring only, not medical advice.
- Labels vary by soil and brand.
- Top near 400 mcg: more is not better.
- Symptoms need clinicians, not math.
Common mistakes
- Scoring one meal instead of the day.
- Daily Brazil nut handfuls past the top.
- Mixing mcg and mg on labels.
- Supplementing without a measured gap.
- Treating percent as a diagnosis.
Try it yourself
Quick checks. Answers sit tucked under each question.
Adult man eating 30 mcg?
Target is 55 mcg. Share is 30 / 55 x 100 = 54.5 %. Gap is 25 mcg more.
Breastfeeding, eating 60 mcg?
Target is 70 mcg. Share is 60 / 70 x 100 = 85.7 %. Gap is 10 mcg more.
Questions
How do I score my day?
Divide food mcg by the stage target. Here 40 / 55 x 100 = 72.7 %.
What are the targets?
Kids 30 mcg, teens 50 mcg, adults 55 mcg, pregnancy 60 mcg, breastfeeding 70 mcg.
Which foods carry selenium?
Brazil nuts lead by far, then tuna, halibut, turkey, and eggs. One Brazil nut can pass the whole day.
How do I close the gap?
Add fish, turkey, or eggs. Here 15 mcg more closes the day, far less than one Brazil nut.
Can I overdo selenium?
Yes. More is not better past the tolerable top near 400 mcg. Food first, megadose never.
Does this diagnose deficiency?
No. Intake scoring only; hair, nail, and thyroid signs need clinicians.