Inclusion Criteria:  Aged between 4-6 years; female and male Can be enrolled into kindergarten/school as a normal child. Be willing to drinking milk daily.  Exclusion Criteria:  Milk allergy or intolerance, did not to be used to drinking milk; Had the following diseases/conditions confirmed by a hospital: serious diseases of heart, liver, kidney, brain, hematopoietic system, immunity, thyroid or cancer that need to be hospitalization for more than 1 week or take medication(s) for more than 1 month with the past two years. having infectious diseases, e.g., tuberculosis, hepatitis, etc. Taking vitamin D, calcium tables or nutrient package; Consumed more than 3 times (>600ml) milk each week in the previous month. Be not willing to provide informed consent, or have other conditions that were considered to be unsuitable for the study by the investigators. Increases of body health were out of the range between 5-8 cm in the last year.