If you answered "yes" to five or more questions, Dr. Carlson-Rink says you need more iron in your diet. "The average American women receives 8 to 10 milligrams of iron daily, but for optimum health 15 milligrams are recommended,” she says. “For pregnant women, the recommended amount increases to 30 milligrams. Red meat and organ meat are the highest sources of iron, but for those who avoid meat and those on refined carbohydrate diets, it's often a challenge to get recommended amounts of iron in the diet without using a supplement.”

Dr. Carlson-Rink says one of the best-known iron supplements is called Floradix, used by midwives for decades to increase low iron levels in pregnant and postpartum women. "Liquid supplements like Floradix do not need to be broken down by the body before their active ingredients can be released and absorbed," she says.

Dr. Carlson-Rink advises that infants can also demonstrate symptoms of low blood iron levels when they appear irritable, colicky or have sleep problems. "The best source of iron for infants is breast milk,” she says. “A nursing mother should ensure her iron intake is sufficient for both her own iron needs and the iron needs of her baby.”

Iron deficiency creates fatigue because iron is needed for the manufacture of hemoglobin, a component of red blood cells essential for the distribution of oxygen throughout the body. Low iron levels mean less hemoglobin production and reduced availability of oxygen within the body, making the individual feel tired and continually fatigued.