1. Core Benefits of Sun Exposure for Children's Growth

• Promote bone development and height growth: Sun exposure synthesizes vitamin D, greatly improving calcium absorption and preventing rickets, O/X-shaped legs
• Prevent myopia: Natural light promotes dopamine secretion, inhibits eye axis elongation, and is the most effective way to protect eyes
• Enhance immunity: Reduce colds, allergies, and respiratory infections
• Improve mood and sleep: Stabilize biological clock, making children's mood more stable and sleep better
• Promote growth hormone secretion: Regular sun exposure helps with normal height development

2. Core Benefits of Sun Exposure for the Elderly

• Prevent osteoporosis and fractures: The elderly have poor vitamin D synthesis ability; sun exposure can reduce back pain, leg weakness, and cramps
• Protect the brain and delay dementia: Slow down brain atrophy and reduce the risk of Alzheimer's disease
• Improve mood and reduce depression: Increase serotonin (the "happy hormone") and relieve low mood and loneliness
• Improve sleep: Expose to light during the day for better sleep at night, reducing early awakening and insomnia
• Protect cardiovascular system: Help stabilize blood pressure and improve blood circulation

3. Minimum Effective Daily Sun Exposure Time (Standard Recommendations)

Note: Must be direct outdoor sunlight; sunbathing through window glass is ineffective (glass blocks more than 90% of UVB rays)