1-year-old baby walking a little O-shaped legs may be a normal phenomenon; may also be caused by calcium deficiency. 1. Normal phenomenon: due to the 1-year-old baby bones are not yet well developed, especially just learn to walk stage, the emergence of a slight O-shaped legs most of the normal phenomenon, and genetic factors have a certain relationship. It is recommended that parents usually strengthen the baby’s daily behavioral care, pay attention to increase nutrition, as the baby gradually grows will slowly ease; 2. Calcium deficiency: due to the usual lack of regular supplementation of calcium or vitamin D, long time intake of food containing too little calcium or vitamin D, etc., leading to the onset of rickets in babies, showing the above symptoms of rickets in the active phase. Parents are advised to make a clear diagnosis in time and take calcium or vitamin D supplements as prescribed by the doctor to help the baby improve the symptoms as soon as possible. It is recommended that parents should strengthen the daily care of 1-year-old babies, pay attention to adjusting the structure of complementary foods, ensure adequate sleep, etc., which can help promote normal growth and development, and if you find abnormal symptoms of the baby to consult a doctor in time.