According to competing statistics, between 50 and 70 percent of us don’t get enough vitamin D. Vitamin D is important because it helps our bodies absorb calcium (vital for bone health), and is needed for muscle function, circulation, respiration, brain development and immunity. It’s nearly impossible to get enough vitamin D from your diet, so to ensure adequate levels, many experts now recommend supplementing with at least 2,000 to 5,000 units (IU) a day. You can also go to the source: You can get that much D from 15 minutes to 30 minutes of direct sun exposure.

READ MORE: How to Know If You’re Low on D