The iron in hard water is not the form of iron that a person can absorb. I would not suggest anyone rely on hard well water for an adequate iron intake, especially infants. I would suggest that you discuss this with the doctor who is not recommending iron-fortified formula.
In addition, well water in many areas of the United States is deficient in fluoride, which is necessary to form hard enamel on teeth. Pregnant women, infants, and children up to the age of 12 should take fluoride supplements unless they are on fluoridated city water. This preventive fluoridation has significantly reduced the number of dental cavities in the last 15 years.
Current iron recommendations for infants under the age of one year is iron-fortified formula or breast milk. Iron deficiency anemia is the most common nutritional deficiency in children. WIC (Women, Infants, and Children) is a federal program whose main purpose is providing iron, calcium, vitamin D and vitamin C rich foods to prevent anemia and rickets in children. This program covers pregnant and breastfeeding women, infants, and children up to the age of five. It is very effective in the public health role it serves.
When babies are born, they have enough iron to last four months. This is assuming that the mother had adequate iron in her diet. The baby’s system is connected to the mother’s system by the umbilical cord. The mother’s iron stores serve as an iron pool for the baby’s production of hemoglobin, which is the oxygen carrier of red blood cells. Without an adequate amount of iron, the hemoglobin cannot carry enough oxygen to body tissues. The result is iron deficiency anemia with symptoms of tiredness and weakness.
Red blood cells that carry iron-rich hemoglobin, live only 120 days or four months. Unless there is a continual supply of iron, vitamin B12, vitamin C and folacin from either food or supplements, anemia will result in poorly formed red blood cells that are ineffective carriers of oxygen.
The main source of food for an infant from birth to one year of age is breast milk or infant formula. Breast milk is low in iron, but because breast milk is higher in lactose and contains vitamin C, the iron is better-absorbed (48% absorbed). Cow’s milk, which is the basis for most infant formula, is low in iron and vitamin C. Because of this lower iron content, infant formula companies fortify formula with iron and vitamin C.
Because babies are not started on solid foods until four to six months, babies must rely on breast milk or iron-fortified formulas to prevent iron deficiency anemia. Pabulum cereals are usually iron-fortified to help supplement the infant’s iron intake. Iron-rich foods like liver and red meats are usually not fed to babies until eight to nine months of age. Also, the quantity of iron-rich foods needed to prevent anemia in infants under the age of one is more than an infant could usually eat.