FSHR and Miscarriage: Studies have shown that vitamin D is involved in follicle development and steroid hormone production, promotes follicle maturation and ovulation by inhibiting the expression of AMH receptor and follicle-stimulating hormone receptor, affects embryo quality, promotes granule cell luteinization by inducing the reaction of key steroid enzymes, such as 3β hydroxysteroid dehydrogenase, and maintains progesterone levels to prevent miscarriage (10, 20).