菠菜是人们喜食的蔬菜之一。它有丰富的营养价值,特别是维生素A、钾、铁含量较高。但菠菜也含有令人讨厌的草酸。草酸与某些矿物质结合在一起,特别是易与锌、钙结合,妨碍了机体对锌、钙的吸收。锌是人体内多种酶的构成成分,钙也是人体重要的离子。锌、钙缺乏,创伤愈合延迟,味觉减弱,没有食欲;在儿童生长发育时期如锌、钙缺乏,可致发育延迟,性成熟推迟等。美国营养学家凯尔瑟曾作过一次实验。12名男性自愿受试者,食用不同的实验性饭菜,每种特殊饭菜食用28天。饭菜分为三种。第一 Spinach is one of the vegetables that people eat. It has rich nutritional value, especially vitamin A, potassium, high iron content. But spinach also contains nasty oxalic acid. Oxalic acid and some minerals together, especially with zinc and calcium, hinder the body’s absorption of zinc and calcium. Zinc is the composition of a variety of enzymes in the human body, calcium is also an important ion of the human body. Lack of zinc, calcium, delayed wound healing, weakened taste, no appetite; growth and development of children such as zinc, calcium deficiency, can cause delayed development, delayed sexual maturity and so on. Kelsey, an American nutritionist, once made an experiment. Twelve volunteers, male volunteers, consumed different experimental meals, each for 28 days. Food is divided into three kinds. the first