Why does the baby shake their head at night?

Patient's question:

Detailed medical condition and consultation purpose: Shaking at night

Doctor's answer:

Calcium deficiency is one of the primary factors causing sleep disturbances in infants. Most mothers consider it. Calcium deficiency and reduced blood calcium levels increase the excitability of the brain's vegetative nervous system, leading to night waking, night terrors, and restlessness during sleep. The solution is to supplement the baby with calcium and vitamin D and increase sun exposure.
A. Calcium supplementation: 300-500mg of elemental calcium per day.
B. Vitamin D supplementation: 400-800 IU per day.