 3. Randomization, blinded method, and allocation concealment: Patients meeting the criteria were randomized into experimental group or control group, according to a computer-generated list. The patients in experimental group will receive the treatment of Ejiao compound while the patients in control group will be treated by Polysaccharide iron complex. The study physicians will receive a sealed decoding envelope per treatment, they will not know the identity of the participants, will not handle the study products, will not know the assigned treatment, and will not share their own examination results. After receiving the evaluation by the study physicians and finishing the investigation form, the patient will take her own sealed decoding envelope and go to the pharmacy of the clinical trial center to receive her medication. The staff of the pharmacy of the clinical trial center is responsible for the distribution and return of experimental drugs to patients. All envelopes, sealed or unsealed, will be returned to the investigators at the end of the study. Patients would be required to return boxes whether they are used and unused at each visit and compliance will be assessed by counting the bottles and capsules. 