The best time to sunbathe for calcium is generally around 10 am and 4-5 pm, depending on the length of daylight in different seasons. The absorption of calcium in the human body is inseparable from vitamin D. Sunbathing can help the human body to obtain sufficient vitamin D, which helps the body to take in and absorb calcium and phosphorus, making the bones grow strong and sturdy. Usually, around 10 a.m. and 4-5 p.m. are the best times for sunbathing as there is plenty of sunlight and relatively weak UV rays. The time period for sunbathing varies slightly from season to season, and it is recommended that patients sunbathe at 10-11 o’clock in spring and autumn, 9-10 o’clock in summer, and 11-12 o’clock in winter. The length of each sunbathing session should also be noted, and it is recommended that the duration of exposure be gradually extended from 10-15 minutes at the beginning to about 1 hour. For those who are weak, try not to exceed 30 minutes per sunbathing session. In winter, patients should pay attention to keeping warm when sunbathing outdoors to avoid catching cold. When sunbathing or sunbathing for babies, direct sunlight at noon should be avoided to damage babies’ vision or burn their skin, and attention should be paid to timely hydration.