Why does a 2.5-month-old infant sleep restlessly and startle easily during daytime naps?

A 2.5-month-old infant’s restless daytime sleep and frequent startles may result from immature nervous system development, vitamin D deficiency, or excessive environmental light.

1. Immature Nervous System Development: Immaturity of the nervous system may stem from abnormal brain tissue development or cerebral hypoxia, leading to restless sleep and startles during the day. This can be improved using swaddling techniques—e.g., gently wrapping the infant snugly in a blanket.

2. Vitamin D Deficiency: Insufficient vitamin D can cause neuronal hyperexcitability, resulting in restless sleep and frequent startles. Under medical supervision, vitamin D supplementation may be prescribed for treatment.

3. Excessive Environmental Light: Restless daytime sleep and startles may also occur when the sleeping environment is overly bright or noisy. Improvement can be achieved by drawing curtains to dim ambient light, avoiding open windows, and using gentle patting techniques.