It found that poor vitamin D status also led to an increase in levels of a hormone secreted by the parathyroid.Overactive parathyroid glands are frequently associated with depression.

• 阿姆斯特丹自由大学的研究人员对约1282名年龄在65岁到95岁间的老年人进行了研究，结果发现其中有26人患有重度抑郁，169人患有轻度抑郁。