Selenium may help treat some common scalp problems
A meta-analysis performed on 27 studies, totalling 1315 patients, revealed that people who experienced psoriasis, acne and atopic dermatitis showed lower levels of selenium in their blood than in the control group [15].
This may suggest selenium could play a role in the development and treatment of common scalp problems, such as scalp psoriasis, scalp acne or atopic dermatitis [16].
However, one study conducted on 69 patients with psoriasis revealed no improvement in patients who received selenium supplementation.
Similarly, while some research indicates that selenium deficiency can exacerbate symptoms of atopic dermatitis [16], a clinical trial conducted on 60 adults with this condition showed no improvement after 12 weeks of selenium supplementation [17].
Selenium has also been found by one study [21] to have antimicrobial properties that were effective in vitro against certain bacteria, some of which are known to cause scalp folliculitis.
However, there are no studies to show that supplementing selenium would be effective in killing this bacteria in humans.
When it comes to dandruff and seborrheic dermatitis, selenium sulphide shampoos are frequently recommended as treatment. This means that selenium can play a role in improving these conditions, but not alone and not through dietary supplements like hair gummies or tablets.
That is because ingesting it does not affect the microbes on the surface of your scalp. However, applying a selenium sulphide shampoo topically on your scalp has been found to reduce irritation and itching [23].
To sum things up, further research is needed to determine the relationship between selenium levels and frequently occurring scalp problems.