iron stores compared with non-vegetarians and have a higher risk of iron deficiency anemia. Lacto-ovo-vegetarians that overly rely on dairy consumption may lead to an elevated calcium intake which can affect iron absorption. The recommended iron intake for vegetarians is 180% that of nonvegetarians due to the bioavailability of non-heme iron. Although a lower percentage of non-heme iron is absorbed by the body, greater total amounts of non-heme iron are concentrated in many non-meat sources of iron, and therefore breakfast cereals, eggs, nuts, seeds, and legumes (including soy foods, peas, beans, chickpeas, and lentils) are significant sources of iron, and a well-planned vegetarian diet should not lead to iron deficiency. Non-heme iron is more sensitive to both inhibitors and enhancers of iron absorption: Vitamin C is an iron absorption enhancer; the main inhibitors for most people are phytates (e.g. legumes and cereal grains), but other inhibitors include tannins (from tea and wine), calcium, and polyphenols. Iron is an integral part in the chemical structure of many proteins and enzymes, which maintain good health. In humans, iron is an essential component of proteins involved in the transport of oxygen of red blood cells. Iron also helps regulate cell growth and cellular differentiation. Zinc A 2013 review found that zinc intake and serum zinc concentrations were significantly lower in populations that follow vegetarian diets compared with non-vegetarians. Phytates in many whole grains, and dietary fiber in many plant foods may interfere with zinc absorption, and marginal zinc intake has poorly understood effects. Vegetarians may need more than the US Recommended Daily Allowance of 15 mg of zinc each day to compensate if their diet is high in phytates. Major plant sources of zinc include cooked dried beans, edible seaweed, fortified breakfast cereals, soy products, nuts, peas, and seeds. Iodine One study reported a "potential danger of [iodine] (I) deficiency disorders due to strict forms of vegetarian nutrition, especially when fruits and vegetables grown in soils with low [iodine] levels are ingested." Iodine, however, is usually supplied by iodized salt and other sources in first world countries. Other significant vegetarian sources of iodine include edible seaweed and bread made with dough conditioners. Health effects Evidence suggests that vegetarian diets have beneficial effects on blood lipids and that vegetarians have a reduced risk of cancer, cardiovascular disease, hypertension and type 2 diabetes. See also Vegetarian cuisine Vegan nutrition The China–Cornell–Oxford Project in the 1980s