Fig. 1

The forest plot of interactions between quartile of vitamin D and estradiol on low skeletal muscle mass. Adjusted for age, residence, marital status, educational level, smoking status, drinking status, physical activity, BMI, FM, triglyceride, menopausal status, and dietary energy. Presented the forest plot of interactions between quartile of vitamin D and estradiol on low skeletal muscle mass among middle-aged and elderly women. The significant interactions between vitamin D Q1 and estradiol Q2, vitamin D Q1 and estradiol Q3, vitamin D Q2 and estradiol Q1, vitamin D Q3 and estradiol Q3 were stably reflected in the final model (P for interaction < 0.05), after adjusting potential confounding factors