a narrow opening produced by cleavage or separation of parts. 2. cleavage (def 1). 3. Anatomy. a natural division or groove in an organ, as in the brain. verb (used with object), fissured, fissuring. 4. to make fissures in; cleave; split.
A diet rich in potassium helps to counterbalance some of sodium's harmful effects on blood pressure. Foods that are good sources of potassium are listed in the Food Sources of Potassium table on the next page.
This nutrient is particularly important for the synthesis of collagen, which forms the basis of a matrix of fibers that gives your skin support. Vitamin C is also a powerful antioxidant that helps shield your cells from oxidative damage. Women require 75 milligrams of vitamin C daily, while men need 90 milligrams.