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Some perspective on what is, and isn’t, vitamin D deficiency
I spoke with osteoporosis expert Dr. Joel Finkelstein, associate director of the Bone Density Center at Massachusetts General Hospital, whose research in this field spans over three decades. He agreed with the authors of the NEJM article that we are currently overscreening for vitamin D deficiency, and overtreating people who are getting enough vitamin D through diet and sun exposure. “Vitamin D has been hyped massively,” he states. “We do not need to be checking the vitamin D levels of most healthy individuals.”
He points out that from an evolutionary standpoint, it doesn’t make sense that higher vitamin D levels would be beneficial to humans. “Vitamin D is actually quite hard to find in naturally occurring food sources,” he points out. “Yes, we can get vitamin D from the sun, but our bodies evolved to create darker skin in the parts of the world that get the most sun. If vitamin D is so critical to humans, why would we evolve in this way, to require something that is hard to come by, and then evolve in such a way as to make it harder to absorb?”