Yes, you can take zinc and selenium together. Many combined tablets contain both, and the NIH Office of Dietary Supplements fact sheets do not list them as a pair that interferes with each other. What matters more is the amount: adults should keep their total intake, food included, under EFSA's upper levels of 25 mg of zinc and 255 µg of selenium a day, and take zinc at a different time from an iron supplement.
Below you will find what EU rules allow to be said about both minerals, how the forms differ, how to read the dose on the label, and when to check with a doctor first.
Zinc and selenium benefits: what the EU allows
Both minerals have health claims authorised under Regulation (EU) No 432/2012. A product may use them when its daily dose gives at least 15% of the nutrient reference value (NRV). All the zinc and selenium products in this article give 150% or more.
Permitted claims for zinc include:
- Zinc contributes to the normal function of the immune system.
- Zinc contributes to the maintenance of normal skin.
- Zinc contributes to the maintenance of normal hair.
- Zinc contributes to the maintenance of normal nails.
- Zinc contributes to the maintenance of normal bones.
- Zinc contributes to the maintenance of normal vision.
- Zinc contributes to normal cognitive function.
- Zinc contributes to the maintenance of normal testosterone levels in the blood.
- Zinc contributes to the protection of cells from oxidative stress.
For selenium the permitted claims are:
- Selenium contributes to normal spermatogenesis.
- Selenium contributes to the maintenance of normal hair.
- Selenium contributes to the maintenance of normal nails.
- Selenium contributes to the normal function of the immune system.
- Selenium contributes to the normal thyroid function.
- Selenium contributes to the protection of cells from oxidative stress.
Each claim describes keeping a normal function. None of them promises an improvement or treats a condition, and a higher dose does not make any claim stronger.
Together or apart, and what time of day
Combined products such as OstroVit Biotin Plus put 15 mg of zinc and 100 µg of selenium in one tablet, taken once a day. If you buy them separately, you can swallow both at the same meal.
For zinc, the meal matters more than the hour. Zinc on an empty stomach makes some people feel sick, and most zinc labels in our range say to take it with or after a meal: OstroVit picolinate and Triple Zinc after a meal, NOW Foods with a meal. Morning or evening makes no difference on the labels, so pick the meal you never skip.
Selenium has no special timing. The NOW Foods label says with a meal; Swanson gives no time at all.
The pairing to avoid is zinc with an iron supplement. More on that below.
Zinc forms and elemental zinc
Zinc in a supplement is always bound to something, and the label must state the elemental zinc, meaning the zinc alone. 15 mg of zinc as picolinate and 15 mg of zinc as gluconate give you the same 15 mg of zinc. The compound around it weighs more, and its share differs by form:
| Form | Zinc bound to | Zinc share of the compound, about | In our range |
|---|---|---|---|
| Picolinate | picolinic acid | 21% | OstroVit zinc picolinate 15 mg |
| Bisglycinate (chelate) | two glycine molecules | 31% | Swanson Albion chelated zinc 15 mg |
| Citrate | citric acid | 31% | part of OstroVit Triple Zinc |
| Gluconate | gluconic acid | 14% | part of OstroVit Triple Zinc; Swanson 30 mg |
The share column is chemistry, worked out from each compound's formula. It explains why a 15 mg zinc capsule can hold a compound weighing several times as much. It says nothing about how much you absorb.
On absorption, NIH ODS reports that zinc citrate and zinc gluconate are absorbed similarly, at about 61% in young adults, and zinc oxide at about 50%. We have not found comparable figures for picolinate and bisglycinate, so we do not rank them. OstroVit Triple Zinc gives 5 mg from each of gluconate, picolinate and citrate.
OstroVit
Zinc Picolinate, 15 mg
OstroVit
Triple Zinc, 15 mg, 90 CapsulesSelenium forms: selenomethionine or sodium selenite
L-selenomethionine is selenium built into the amino acid methionine. NIH ODS describes it as the main form of selenium in food, and reports that the body absorbs more than 90% of selenomethionine but only about 50% of the selenium from sodium selenite. Selenomethionine can also be stored in body proteins in place of methionine.
Selenium yeast, such as SelenoExcell, is yeast grown on a selenium-rich medium. The label states the selenium in µg. Sodium selenite and sodium selenate are inorganic forms that show up mostly in multivitamins.
Higher absorption is the reason to count selenium carefully. With 100 µg or 200 µg per capsule, most of it reaches your body, so the upper level is closer than the label number suggests.
How much: NRV and EFSA upper levels
The NRV on a label is a reference for comparing products. EFSA's dietary reference values tell you what adults need, and the tolerable upper level (UL) is the most you should get every day from food and supplements together.
| Zinc | Selenium | |
|---|---|---|
| NRV on labels | 10 mg | 55 µg |
| EFSA reference intake, adults | 7.5 to 12.7 mg for women, 9.4 to 16.3 mg for men, depending on phytate in the diet | 70 µg (adequate intake) |
| EFSA upper level, adults | 25 mg | 255 µg |
| Per daily dose in this article | 15 mg | 100 µg or 200 µg |
Phytate is a compound in whole grains and legumes that binds zinc, which is why EFSA's zinc figure rises for diets rich in it.
EFSA set the 25 mg zinc limit to protect copper status: high zinc intake over a long time reduces copper absorption, and NIH ODS notes it can lead to copper deficiency. For selenium, NIH ODS lists garlic breath, a metallic taste, and hair and nail loss or brittleness as signs of chronic excess. One product in our range gives 50 mg of zinc per tablet, twice the EFSA upper level, so we do not feature it here; take that dose only on a doctor's advice.
Brazil nuts are the food to watch. NIH ODS lists about 544 µg of selenium in 28 g, which is 6 to 8 nuts, and the content varies with the soil the trees grew in. If you eat them often, count them before adding a selenium capsule.
Iron, calcium and medicines
According to NIH ODS, iron supplements of 25 mg or more taken at the same time as zinc can reduce zinc absorption. If you take both, put them at different meals, for example zinc with lunch and iron in the morning. Iron products are in the iron collection.
Many people keep calcium supplements apart from zinc too. The evidence for calcium is weaker than for iron, but taking them at different meals costs you nothing.
Zinc reduces the absorption of quinolone and tetracycline antibiotics, and of penicillamine. NIH ODS describes spacing them by a few hours. Ask your pharmacist for the timing that fits your medicine.
Talk to a doctor before taking zinc or selenium if you are pregnant or breastfeeding, take prescription medicine, or want a dose above the label. Most single-mineral labels in our range do not recommend use during pregnancy, and the OstroVit Biotin Plus label asks pregnant women to consult a doctor first.
How to choose zinc and selenium
- Check what you already take. Multivitamins and hair formulas often contain zinc, selenium or both.
- Read the elemental amount and the % NRV per daily dose, not per tablet.
- Add up every source, food included, and stay under 25 mg of zinc and 255 µg of selenium a day.
- Pick a zinc form you are happy with and compare price per day. For selenium, check whether the label says selenomethionine, selenium yeast or selenite.
- Decide between a combined tablet and two separate products. Separate products let you set each dose; a combined one is one tablet a day.
- If you take iron, antibiotics or other medicine, plan the timing with your pharmacist.
Read the daily dose line, not only the front of the pack. The Swanson zinc gluconate 30 mg tablet has a daily dose of half a tablet, which is 15 mg. The NOW Foods selenium 100 µg tablets allow one or two a day, so the daily dose can be 200 µg.
Zinc products are in the zinc collection and selenium in the selenium collection. Each product card shows the amount per daily dose and the price per day.
FAQ
Can I take zinc and selenium together?
Yes. Many combined tablets contain both, and NIH ODS does not list them as an interacting pair. Keep the total of each under the EFSA upper level.
When is the best time to take zinc?
With or after a meal, as most labels in our range say. Morning or evening is up to you. Keep it apart from iron supplements.
What are zinc and selenium good for?
Only the EU-authorised claims listed above may be used, for products with at least 15% NRV per daily dose. Two examples:
- Zinc contributes to the normal function of the immune system.
- Selenium contributes to the normal thyroid function.
How much zinc per day is safe?
EFSA set the adult upper level at 25 mg a day from all sources. A 15 mg supplement leaves room for zinc from food, but add up any other products you take.
Which form of zinc is best?
The EU claims apply to zinc in any form. NIH ODS gives similar absorption for citrate and gluconate and has no comparable figures for picolinate or bisglycinate. Compare zinc per daily dose and price per day.
How many Brazil nuts equal a selenium supplement?
NIH ODS lists about 544 µg of selenium in 6 to 8 nuts, but content varies widely. One or two nuts can already match a 100 µg capsule, so count them if you take selenium as well.
Sources
- Commission Regulation (EU) No 432/2012, list of permitted health claims (EUR-Lex)
- Zinc, fact sheet for health professionals (NIH ODS)
- Selenium, fact sheet for health professionals (NIH ODS)
- EFSA (2023), scientific opinion on the tolerable upper intake level for selenium
- EFSA (2014), scientific opinion on dietary reference values for zinc
Content reviewed by Inese Kalniņa, dietitian.
