Iron is one of the keys to good health and energy levels in women prior to menopause. Foods that provide iron include red meat, chicken, turkey, pork, fish, kale, spinach, beans, lentils and some fortified ready-to-eat cereals. Plant-based sources of iron are more easily absorbed by your body when eaten with vitamin C-rich foods. So eat fortified cereal with strawberries on top, spinach salad with mandarin orange slices or add tomatoes to lentil soup.
Calcium may even be harmful for men, at least in large amounts. The worry is prostate cancer, and two Harvard studies have raised the alarm. In 1998, the Health Professionals Follow-up Study found that a high consumption of calcium from food or supplements was linked to an increased risk of advanced prostate cancer. The risk was greatest in men who got more than 2,000 mg a day. More recently, the U.S. Physicians' Health Study reported that a high consumption of calcium from dairy products appeared to increase a man's risk of prostate cancer by up to 37%. A study from the Fred Hutchinson Cancer Research Center in Seattle also found a link between calcium and advanced prostate cancer.
A year later, a second Harvard study added to the concern. The Physicians' Health Study of 20,885 men did not evaluate diet per se, but it did measure the blood levels of ALA in 120 men who developed prostate cancer and compared them with the levels in 120 men who remained free of the disease. Men with moderately high ALA blood levels were 3.4 times more likely to develop prostate cancer than men with the lowest levels; curiously, though, men with the very highest levels were only 2 times more likely to get the disease.
The same protein ingredients marketed as dietary supplements can be incorporated into meal replacement and medical food products, but those are regulated and labeled differently from supplements. In the United States, "meal replacement" products are foods and are labeled as such. These typically contain protein, carbohydrates, fats, vitamins and minerals. There may be content claims such as "good source of protein", "low fat" or "lactose free." Medical foods, also nutritionally complete, are designed to be used while a person is under the care of a physician or other licensed healthcare professional. Liquid medical food products - example Ensure - are available in regular and high protein versions.
For instance, foods rich in vitamin E and beta-carotene are healthy and can help reduce cancer risk. However, the U.S. Preventive Services Task Force (USPSTF) and the American Academy of Family Physicians (AAFP) recommend against taking vitamin E or beta-carotene for the prevention of cardiovascular disease. People who smoke or are at risk for lung cancer also should avoid beta-carotene. It can increase their risk of lung cancer.