Vitamin D3
Review
Most people are deficient in it, with several science-backed benefits. A staple among nutritional supplements, which you can read about here: https://fitclan.sk/zdravie/slnecny-vitamin-d-vacsina-ludi-ho-ma-nedostatok-robi-nas-stastnejsich-patri-medzi-najlepsie-doplnky-vyzivy/. We might like to see a combination with vitamin K2 in the future, but otherwise, this D is another of the classics that almost everyone can use as a basic supplement.
As I'm sure you know, we get vitamin D from the sun. However, in our area we are not able to absorb this vitamin from the sun during the winter season, so it is important to supplement it. It affects a large part of the factor in our body. Such a major one is probably immunity, which we all need during this period.