A full rundown of zinc and copper benefits would fill up a small book — with vital roles in everything from cardiovascular function, to hormone production, to keeping your immune system strong. In fact, zinc alone is responsible for over 300 enzymatic reactions in your body.

But even though both zinc and copper occur naturally in vegetables, fruits and meats…chances are you’re not getting enough — even if you’re following the Bulletproof Diet.

After all, nutrient depletion in modern soil is steadily driving down the vitamins and minerals you’re getting bite-for-bite compared to the produce your parents and grandparents ate (even if you buy organic). And not just a little bit — compared to a generation or two ago, copper levels in contemporary foods are as much as 75% lower than they used to be.

Meanwhile, because your body doesn’t store zinc, it needs to be replenished daily...

While the best pound-for-pound food source for zinc is oysters, you’re probably not throwing back enough oysters on the half-shell each day to make a difference, even if you like them. What about other food sources for zinc? Red meat, nuts, legumes, and whole-grains also contain zinc, but in markedly lower amounts. And you may want to avoid consuming too many nuts, legumes, and whole-grains daily for other reasons, like their high levels of phytates and other “anti-nutrients,” which can suppress zinc absorption from your diet.

The takeaway? Even if you have plates piled with fresh-grown veggies washed down with platters of Oysters Rockefeller daily, supplementing with extra zinc and copper is likely one of the easiest “quick win” upgrades you can add to your diet.