During the first year of life, an infant's body weight triples, and significant brain growth occurs. Accordingly, baby's nutritional needs increase more rapidly in the first year than at any other period of his or her life. During this period of rapid growth, the weaning process begins. Following is a survey of key nutrients that should be included in a nutritionally sound weaning diet.

Protein
Protein is important for building and maintaining body tissues. Some good sources of high-quality protein are chicken, fish, beef, pork, lamb, turkey, and liver. Vegetable sources of protein include legumes (such as beans, lentils, peas, and soybeans), nuts, and seeds.

Carbohydrates
Carbohydrates supply your baby with energy. Cereals and breads are good sources of carbohydrates. Parents should choose iron-fortified infant cereals, especially for breastfed infants, to help prevent iron deficiency.

Nucleotides
Nucleotides improve immune response and decrease the incidence of diarrhea in infants. Although the body can make its own nucleotides, infants may need extra nucleotides to meet the demands of their fast-growing bodies. Early weaning foods are typically poor sources of nucleotides. Some follow-on formulas are fortified with nucleotides.

Wyeth's premium follow-on formula, PROMIL* GOLD, is fortified with 5 beneficial nucleotides.

AA and DHA
The fatty acids arachidonic acid (AA) and docosahexaenoic acid (DHA) are particularly important in the period of significant brain growth that occurs during the second 6 months of life. AA and DHA play a considerable role in mental and visual development during this time. Because most weaning foods are poor sources of AA and DHA, a fortified follow-on formula can be an important source of these fatty acids.

PROMIL GOLD is fortified with preformed AA and DHA.

Vitamins and minerals
Vitamins and minerals are essential for normal body functioning and growth. Fruits and vegetables are excellent sources of many vitamins and minerals. If you choose to prepare these foods yourself, rather than buy commercial baby food products, use fresh or frozen fruits and vegetables. Avoid using canned products, which may contain added sugar or salt.

Here are details about some important vitamins and minerals:

• Vitamin C: Children can get vitamin C from citrus fruits and various vegetables. Their bodies need vitamin C both to form certain chemicals and to put others, including one of the B vitamins, to use. Vitamin C also plays a key part in helping children's bodies absorb iron. Children who do not have enough vitamin C in their diet may develop weakness in their bones, anemia, and other medical conditions.
  
  
• Vitamin D: Sunlight helps the body make vitamin D, and, for some children, sunlight alone may provide sufficient levels of this important vitamin. Vitamin D is crucial because the body uses it to help get calcium into the bones. This is why vitamin D is sometimes added to cow's milk (this is called "fortified" milk). However, most other dairy foods children like to eat are not fortified with vitamin D. Foods such as cheese and yogurt give children calcium but do not have any vitamin D. Dietary sources that are fortified with vitamin D are a better choice than vitamin supplements. Children who don't have enough vitamin D in their diet may develop rickets, a painful disease that can cause bones to become unnaturally flexible or misshapen.
  
  
• Vitamin A: This vitamin is important in helping your baby's eyesight develop. It also plays a part in making bone cells work. Children who do not get enough vitamin A can have problems such as night blindness and poor growth. They can also be less resistant to infection. This important vitamin has a number of dietary sources, including eggs, cheese, and liver.
  
  
• The B vitamins: All B vitamins help give children energy and help them build brain cells. Vitamin B₁ and niacin (which is part of the B-complex chain) help the body produce energy in its cells. Vitamin B₆ helps the body fight illness and infection. B₁₂ is used to develop red blood cells. The right amount of B vitamins in their diet helps protect children from slowed growth, anemia, eye troubles, nerve damage, and heart problems. Foods such as bread, whole grains, and liver are sources for B vitamins. Each B vitamin can also come from other specific diet sources, such as beans and pork for B₁ or meat, fish, eggs, and milk for B₁₂.
  
  
• Iron: Iron plays a part in many processes inside the body, including the delivery of oxygen to cells. Because babies' physical development and mental development are so rapid at this age, the need for iron is greatly increased. Unfortunately, a weaning diet of solid foods and cow's milk during this time can be low in iron. Not only is cow's milk a poor source of iron, but the iron it does contain is poorly absorbed by the body. In fact, the use of cow's milk has been linked with iron deficiency and anemia in children up to 24 months of age. Iron deficiency early in childhood can lead to long-term effects on mental development that may be irreversible. Experts recommend that an iron-fortified formula be used to ensure adequate intake. PROMIL GOLD is fortified with an appropriate level of iron to help prevent iron deficiency.
  
  
• Zinc: Many of the body's hormones and chemicals called enzymes depend on zinc to perform their functions. Zinc is also related to babies' ability to grow.
  
  
• Calcium: Calcium is one mineral that babies need for proper bone growth. Research shows that children need to have the right amount of calcium in their diet to lessen the risk of accidental bone fractures later in life.