The best food sources of easily absorbed iron are animal products. Iron from vegetables, fruits, grains, and supplements is harder for the body to absorb. Mixing lean meat, fish, or poultry with beans or dark leafy greens at a meal can improve absorption of vegetable sources of iron up to three times. Foods rich in vitamin C also increase iron absorption. Iron deficiency is the most common nutritional deficiency worldwide.
Deficiency occurs in the form of iron deficiency anemia.
Iron deficiency and anemia can occur during periods of rapid growth, during pregnancy, and among women who are menstruating more than usual. It can be associated with any type of intestinal loss of blood, frequent donation of blood, or from the inability to absorb iron efficiently. Initial symptoms of iron deficiency anemia are fatigue and lack of energy. Dizziness, weight loss, headaches and lowered immunity can also occur. Symptoms include fatigue, anorexia, dizziness, nausea, vomiting, headache, weight loss, shortness of breath, and possibly a grayish color to the skin.