Night crying is a normal physiological manifestation in babies. However, excessive night crying can affect sleep quality and overall health, put psychological pressure on parents, and increase the risk of postpartum depression. Besides factors like environment, digestion, and psychology, a lack of essential micronutrients can also make babies uncomfortable and lead to restless sleep.

Vitamin D plays a vital role in bone and muscle health, aiding calcium absorption. Vitamin D deficiency can cause babies to cry due to bone and muscle aches, poor sleep, or irritability. It can also affect a baby's ability to regulate emotions and behavior.

According to Dr. Nguyen Van Toan from the Neonatal Department of Tam Anh General Hospital, newborns often don't get enough vitamin D due to its low concentration in breast milk and limited exposure to natural sunlight. Babies who are exclusively or partially breastfed should receive vitamin D supplements in drop form with a dose of 400 IU/day, starting from 4 weeks old up to one year old.

A newborn baby is being cared for at Tam Anh General Hospital. Photo: *Tam Anh General Hospital*

Calcium is the main component of bones and plays an essential role in the nervous and muscular systems. When babies lack calcium, ionized calcium levels in the blood decrease, increasing the excitability of the neuromuscular system. This can lead to symptoms like being easily startled, restless sleep, and night crying.

To prevent and improve calcium deficiency, parents need to ensure a balanced diet for their children according to their age. Increase foods rich in calcium, such as milk, dairy products, small fish eaten with bones, and eggs, along with vitamin D for effective calcium absorption. Mothers of exclusively breastfed babies should ensure their own diet is rich in calcium and vitamin D and provide adequate morning sunlight exposure for their babies. Babies with calcium deficiencies need supplementation as prescribed by a doctor.

Magnesium helps relax muscles, regulate the nervous system, produce the hormone melatonin, and enhance the neurotransmitter GABA. Magnesium deficiency can make it difficult for babies to sleep and lead to night crying. Parents should supplement magnesium through breast milk or formula as recommended and ensure the mother's diet is rich in green vegetables, nuts, and whole grains. If an exclusively breastfed baby still shows signs of deficiency, they should be taken to a doctor for testing and appropriate supplementation.

Babies lacking iron can also experience restless legs syndrome, causing discomfort and an urge to move their legs, leading to fatigue and poor sleep. Iron deficiency in newborns can cause night crying due to anemia, which affects oxygen transport and nerve function. Parents should take their babies to a doctor for tests, diagnosis, and iron supplementation as directed, while maintaining an iron-rich diet for the mother.

Zinc also plays a vital role in nerve function and sleep regulation. Zinc supplementation can help extend nighttime sleep and total quality sleep duration in infants. Zinc deficiency can also affect neurotransmission, making it difficult for babies to sleep soundly, causing them to be easily startled and cry frequently. In addition to night crying, babies may experience loss of appetite, developmental delays, hair loss, or increased susceptibility to infections. A doctor can accurately diagnose zinc deficiency and guide parents on appropriate supplementation.

Hang Tran