The invention relates to preparations for dietary, food supplement or medical purposes and more specifically to a safe and natural preparation or a composition useful in immunity regulation and/or stimulation and in particular in the building, reinforcement, efficiency, maintenance and regeneration of natural immune defences in a subject. The preparations comprise magnesium, zinc and/or iron, blackcurrent seed oil and/or palm oil, two plant extracts selected from thyme, chickpea and lentil, as well as algae (fucus, wakame, nori), mushroom (shiitake, maitake), and at least one hydrosoluble vitamin and/or vitamin E.