C_T is 100% correct. Whole foods are where it's at, and trying to single out an individual nutrient may cause more harm than it would solve. Potassium in its isolated state can give you a cardiac arrest due to its extreme ability to generate a most powerful muscle contraction. So unless you are 100% certain of a deficiency in a particular micronutrient, it would be best not to delve into what I would call isolated supplementation...especially with your electrolytes!
Including green leafy vegetables plus other vegetables such as sweet potatoes and the cruciferous family of vegetables; the fruit berries and other fruits such as the avocado etc. and you would more than likely cover all your micronutrient needs, including both form of fiber, soluble and insoluble. Zinc for example is great for your immune system, but take a bit over what you need (in supplement form instead of (say) few oysters), and your immune system would suffer for it, causing you to be very lethargic indeed. Can’t beat real wholesome food. Once you've covered your macronutrients needs with well balanced wholesome foods, the micronutrients would take care of themselves.
PS: Macronutrients are all the carbohydrates (including their none digestible and fiberous elements), proteins, fats, and water (or the fluid parts of the whole foods that we eat). Micronutients are all the vitamins and minerals that are found within our foods, in addition to the latest superstars of the micronutrient world we call phytochemicals.
Fadi.