Vitamin A ensures healthy vision and immune system functioning, while the antioxidant properties of vitamin E protect the body’s cells from damage, according to WebMD. Magnesium is essential for regulating heart rate and keeping bones strong, and chromium maintains stable blood glucose levels. Potassium regulates the body’s water balance and supports the nervous and muscular systems.
Vitamin A supplementation treats the dry eye and keratin build-up in the conjunctiva caused by a vitamin A deficiency, reports Mayo Clinic. While more research is needed as of 2015, vitamin A, in combination with carotenoids, may help prevent the vision loss associated with age-related macular degeneration. When given to patients in the palmitate form, vitamin A treats the night blindness and progressive vision loss of retinitis pigmentosa. Early research indicates that large doses of vitamin A combined with vitamin E may expedite healing after photorefractive keratectomy, a laser surgery that corrects nearsightedness.
Magnesium and potassium are macrominerals, essential minerals that are needed in larger amounts than the trace mineral, or micromineral, chromium, explains WebMD. Both magnesium and potassium are required for nerve transmission and muscle contraction. Good dietary sources of potassium include legumes, whole grains, meats and milk. Magnesium is found in leafy and green vegetables, nuts, seeds, and chocolate. Chromium-rich foods include liver, cheeses and brewer’s yeast. This trace mineral interacts with insulin to keep the body’s blood sugar levels in balance.