If there is a strong family history of food allergy on either side of the family, it is advisable that the baby be fed solely breastmilk for the first six months of life. Research has shown that babies with a family history of allergy who are formula fed or supplemented with formula, have more food allergies than infants who are fed breastmilk alone. Prices vary widely and formula can be very expensive. Both liquid concentrate and powder need to be mixed with water before use. Be sure to use very scrupulous sanitation practices and to follow the directions on the can carefully.
Infants can run into medical and growth problems from under or over diluting the formula.
Liquid concentrate is the most popular form, because all you have to do is mix with an equal amount of water. If you have well-water, or are concerned about the safety of your water, have it tested by your local health department or a reputable lab, before using it to make formula. Bottled water is not necessarily safe either, but recent legislation has improved the labeling of bottled water. Read the label carefully to determine the source of any bottled water you use. Baby bottled water is not necessary and is usually expensive.