Iron in foods
If you are looking to improve your iron status through diet, here are the best sources from foods (5-18 mg/100 g food): liver, prune juice, kidney, heart, molasses, pork, beef, sunflower seeds, kidney beans, pinto beans, oyster, clam, lima beans, lentils, navy beans, sesame seeds, tahini, chickpeas, hummous, lamb, egg yolk, rice polishings, rice bran, millet, parsley, Jerusalem artichoke, buckwheat.
Less concentrated iron food sources (1-5 mg/100 g food): walnuts, mustard greens, soy milk, almonds, cashews, chicken, turkey, shrimp, tuna, mackerel, veal, wheat germ, sardines, dandelion greens, butternut squash, dates, prunes, tomato juice, split peas, liverwurst, tortillas, peas, brewer's yeast, raisins, Brussels sprouts, kale, collards, spinach, apricots, peaches, turnip greens, beet tops, whole grain cereals, lentils, kelp, tofu, tempeh, whey powder, watercress, elderberries, endive, cucumbers, chestnuts, chard, barley, Brazil nuts, broccoli, cauliflower, garlic, persimmons, brown rice.
Iron supplements
Most medical doctors recommend 300 mg of ferrous gluconate or ferrous fumarate once or twice daily for iron deficiency. Many different brands of this type of iron supplement are available at a regular pharmacy. These would be fine if they didn't cause black stools, stomach irritation, and constipation in most people taking them. In addition, their absorption into the bloodstream is weak. In severe cases of diarrhea, they might have a role to play as alternatives to narcotics or other toxic constipating drugs. The constipation side effect can sometimes be ameliorated by taking the pharmaceutical iron with a hefty dose of vitamin C (1000 mg or more). As you may know, high doses of vitamin C can cause loose bowel movements.
If you would prefer to use more of a natural iron supplement, I recommend the health food store brand Floradix liquid iron and Floravital (the same, only yeast-free), made in Germany by Salus-Haus and distributed in North America by Flora. Constipation is usually not a problem with these because the iron is in a liquid form and also contains some vitamin B12 and fruit juice concentrates for better absorption. Floradix is also available in a tablet form. I have recommended the Floradix brand with excellent results for over 20 years.
In addition, numerous popular health food store brands make iron citrate, iron aspartate, and iron picolinate supplements, which are all much better tolerated and absorbed than the harsh pharmaceutical iron tablets. They are freely available in the USA; however, the laws governing nutritional supplements is considerably different in Canada, and the asparate and picolinate versions are hard to find there.
Iron can be a double-edged sword. If you are on any iron supplement, it's important to get your blood checked periodically in case of developing iron overload, a risk factor for heart disease, diabetes, cancer, and liver problems. This issue is especially important in men and post-menopausal women who do not have the opportunity of monthly iron loss through menstruation.
Dr. Zoltan Rona