Since premenstrual syndrome (PMS) is one of the most common and debilitating disorders in women, risk factor modification is an urgent health priority. Therefore, this systematic review aimed to summarize and discuss the outcomes of observational and interventional studies in humans regarding the relationship between Calcium and PMS. PubMed, Scopus, ISI web of sciences and Google scholar were searched up to January 2019 to identify relevant studies. The Newcastle-Ottawa and Jadad scales were used for quality assessment. A total of 14 studies (8 interventional and 6 observational) met our inclusion criteria. Majority of the studies showed that not only serum calcium levels are lower in PMS subjects, but also calcium supplementation could significantly improve the incidence of PMS and its related symptoms. This systematic review suggests a beneficial role for calcium in PMS subjects. However, in order to draw a firm link between calcium and PMS, further dose-response clinical trials with larger sample size and better methodological design are warranted.

Gastric cancer as a common cancer is a multi-factorial disease that is dependent on parallel effects of environment and genetics. Endogenous and host factors, including gender and several genetic backgrounds are known risk factors also many environmental factors, including smoking, diet, infection and increasing body weight and body mass index (BMI) are associated with the gastric cancer. Epidemiological data have consistently demonstrated a positive relation between obesity and gastric cancer, whereas mechanistic studies have sought to uncover obesity related carcinogenic pathways. Biological mechanisms and the relationship between obesity and cancer are complex and not well understood. Different effective factors include obesity-related hormones and adipokines, growth factors, modulation of energy balance and calorie restriction, inflammatory processes and multiple signaling pathways that affect cancer cell promotion and progression. In this review, we will discuss the recent advances in the understanding of the association of obesity changes in the gastric cancer.