@roger,
Iron deficiency, which is the most common nutritional deficiency, can cause anemia, which prevents your body's cells from getting enough oxygen. Symptoms of iron-deficiency anemia include weakness, headache, dizziness, drowsiness, fatigue and irritability. Teen girls and women who are menstruating and children and adolescents undergoing rapid growth periods are especially at risk for iron deficiency and iron-deficiency anemia. Infants and children are also at increased risk of iron deficiency.