Can You Get Enough Vitamin D From the Sun?

Can summer sun give you enough vitamin D? Chances are, no. “Most people don’t get enough unprotected sun exposure to make enough vitamin D,” says Ken Redcross, MD, a holistic physician and author of Bond: The 4 Cornerstones of a Lasting and Caring Relationship with Your Doctor.

Based on research and his years of experience in routinely testing patients’ vitamin D levels, Redcross estimates that 80–90 percent of Americans are low in the sunshine vitamin, even in warm Southern states. Fatigue, anxiety, recurrent infections, and feeling “not yourself” are common signs.

In science speak, vitamin D is a “prohormone,” meaning a hormone precursor. Redcross explains it this way: “Think of it as the key to opening genes that have healing powers.” Most immune cells need vitamin D to do their jobs, and it’s essential for a healthy heart, muscles, bones, and mood, and to ward off diabetes and autoimmune conditions.

When people take enough vitamin D for 4–6 weeks, they typically have more energy and feel better overall. “They experience a new sense of well-being,” says Redcross.