Genetics play a huge role in determining a person’s height. How tall and how fast a child can grow will depend on the combination of genes inherited from both parents. Experts estimate that about 40‒70% of a person’s height is determined by genetic transmission.3
Children need enough nutrition and energy to grow. Both macronutrients (particularly protein) and micronutrients (vitamins and minerals) are essential for optimal growth. Nutrition has a stronger impact in establishing adult height during the first 2 years of life while genetic influences may play a more significant role in older children.6
The environment in which the child lives in can have a positive or negative impact on growth. Lack of proper sanitation, poor housing conditions, food contamination, and exposure to air pollution can hamper growth.8 Lack of love, or living in harsh and stressful family environments, can cause growth failure even if a child is eating enough.9,10
Hormones have an important role in stimulating growth. Some children are born with or develop medical conditions where the body cannot produce enough hormones, such as hypothyroidism (lack of thyroid hormone) or growth hormone deficiency. These conditions result in short stature in affected children.7
.png)
Growth hormone is a protein substance produced by the pituitary gland. This gland is a small, pea-sized organ located at the base of the brain (Figure 1). It makes, stores and releases growth hormone into the bloodstream in short bursts or pulses.11
Figure 1. The Pituitary Gland
How Growth Hormone Works
One of the most important actions of growth hormone is its effects in stimulating the growth of long bones. This action depends on another protein called insulin-like growth factor 1 (IGF-1), which is produced mainly by the liver (Figure 2).11
Figure 2. Actions of Growth Hormone
The liver secretes IGF-1 in response to growth hormone, which in turn stimulates new cell growth in the cartilage located near the ends of the long bones.11 This thin layer of cartilage is known as the epiphyseal plate or growth plate (Figure 3). The formation of new bone in this area allows the bones to elongate and results in height gain in children.12
Apart from linear growth, growth hormone also plays a role in regulating metabolic functions. It tells our body how to use protein to build muscles, breakdown carbohydrate and fat for fuel, and help maintain blood sugar levels.11
Figure 3. Growth Plates
