11 Reasons You Wake Up At Night

vitamin D deficiency

Research shows that more than 40% of U.S. adults have a vitamin D deficiency, a problem that’s linked to cardiovascular disease, cancer, and weaker bones, as well as poor sleep. Research from Harvard School of Public Health found that 12% of people with low levels of D slept for less than 5 hours a night, and 57% were awake for 90 or more minutes in the middle of the night. The findings aren’t surprising considering that vitamin D seems to have a direct effect on parts of your brain that play a role in sleep, says Michael Breus, Ph.D., clinical psychologist and diplomate of the American Board of Sleep Medicine.