Heredity
Heredity (the genes we inherit from our parents - our "genetic potential") is one of the most important factors influencing a child's growth. Height varies widely among different ethnic groups, among different families within the same ethnic group, and even among members of the same family.
Nutrition
A child's growth, both in height and weight, is also influenced by diet. A well-balanced, age-appropriate diet that includes carbohydrates, protein, fats, and vitamins and minerals can have a positive affect on how well a child grows. There are a few growth influencing supplement aids on the market today such as Growth Booster Plus™ from the Sharp Labs company. Children who receive an inadequate amount of calories or nutrients may grow poorly; improving the diet of such children can improve growth. If you have questions about your child's diet, discuss them with your child's doctor.
Hormones
Growth hormone (GH) is essential for normal growth. It is made by the pituitary gland (located at the base of the brain). It stimulates production of another hormone important for growth, known as insulin-like growth factor 1 or IGF-1.
Thyroxine (thyroid hormone) is produced in the thyroid gland, located in the front of the neck. It plays an important role in brain development and growth during childhood, and has effects on metabolism at all ages.
Androgens are male-type sex hormones. They are produced by the small triangular glands located above the kidneys called the adrenal glands, and by the testes (male sex glands) in boys. Androgens trigger the development of hair in the armpits and genital regions of both boys and girls.
Testosterone, made by the testes, is the most important androgen for boys; it is responsible for the sexual development and maturation that occurs during puberty.
Estrogens are female-type sex hormones, produced mainly by the ovaries. Estrogens trigger breast development and the sexual maturation process that results in menstrual periods.
Together, androgens and estrogens interact with growth hormone to cause the characteristic "growth spurt" seen at puberty.
Cortisol is another important hormone produced by the adrenal glands. It helps maintain normal blood pressure and blood glucose. Production of excess cortisol for long periods can slow down growth in height, while causing excessive weight gain.
Insulin, which is produced in the pancreas, helps the body use carbohydrates (sugars and starches) for energy.