Why Do Children Grow Faster In The Spring?

Evidence for Seasonal Growth Patterns

A 2015 study of 760 Danish students aged 8 to 11 examining seasonal height and weight changes in children revealed that the greatest growth was recorded in the spring around April and May. Similar findings were also reported and published in a 2022 paper that tracked the development of thousands of Texas children from kindergarten to fifth grade, confirming strong growth spurts occurred in spring and early summer while slowing down the rest of the year. Again, spring was the standout season for accelerated height increases.

So what’s behind this pattern?

1. Increased Exposure to Sunlight (Vitamin D)

One key factor is sunlight exposure. Longer days and increased time outside during the spring boost vitamin D production. Vitamin D plays a crucial role in calcium absorption and bone growth, especially during periods of rapid skeletal development.

Deficiencies in vitamin D have been linked to slower growth rates and even conditions like rickets in severe cases. As children spend more time outdoors after a long winter, their vitamin D levels naturally rise, supporting optimal growth conditions.

2. Changes in Melatonin and Hormonal Regulation

Light exposure doesn’t just affect vitamin D. It also plays a role in regulating melatonin, a hormone produced in the pineal gland that influences sleep and circadian rhythms.

Increased daylight hours in spring lead to lower melatonin levels during the day, which may result in changes to growth hormone (GH) secretion. GH is mostly released during deep sleep, but its production is also influenced by seasonal light cycles. Some research suggests that longer days may enhance GH activity, indirectly supporting height gain.

3. Improved Sleep and Physical Activity

After the slower, often more sedentary winter months, children tend to become more physically active in the spring. Physical activity is known to stimulate bone growth and muscle development, especially when it involves weight-bearing movements like running, jumping, and climbing.

In addition, better sleep—which often accompanies increased daytime activity—can also support growth, since growth hormone is predominantly secreted during deep sleep phases.

4. Nutritional Patterns

While more research is needed, some studies suggest that children may have better appetites and improved dietary intake in the spring. Fresh produce becomes more available, and increased outdoor time may correlate with more regular mealtimes. A well-balanced diet rich in protein, calcium, and essential vitamins supports growth at every stage.

Conclusion: Growth Has a Season

Growth is a year-round process, but spring may give children the ideal conditions for a boost: more sunshine, more movement, better sleep, and improved nutrition. While every child grows at their own pace, don’t be surprised if last season’s jeans start looking a little short this spring!

If you're a parent or caregiver, encouraging outdoor play, balanced meals, and a healthy sleep routine can help support your child’s natural growth rhythms—no matter the season.