Babies crying and not sleeping in the second month may be due to physiological factors, vitamin D deficiency, intestinal cramps and other factors. 1. Physiological factors: for example, the environment is too hot, too cool, too much moisture; eating too much or too little food, diapers are too thick, stuffy, etc., may affect the baby’s sleep quality, resulting in nighttime sleep and crying, poor sleep quality. 2. Vitamin D deficiency: a prolonged lack of vitamin D, not timely supplementation, may cause rickets, resulting in muscle spasms, seriously affecting the quality of sleep, resulting in babies crying at night. 3. Intestinal spasm: related to the smooth muscle contraction, the pain is serious when it affects the baby’s sleep, resulting in sleep disturbance, crying, loss of appetite and so on. Baby two months crying and not sleep may also be with other reasons, it is recommended that should be timely medical treatment, and then targeted treatment, so as not to delay the condition, affecting the baby’s physical development.