How Vitamin D & Calcium Work Together To Support Healthy Bones*

When you think about vitamin D, sunshine and strong bones probably come to mind. And while we've learned for decades that vitamin D actually has a whole slew of whole-body benefits (including supporting your immune system and promoting proper thyroid function, among others), helping to keep your bones healthy and strong is certainly still a foundational role of this fat-soluble micronutrient worth raving about.* (Especially considering we lose bone mineral density as we age1!)

One of the major ways in which vitamin D does so much good for your bones is through its relationship with calcium, the major structural building block of your bones and teeth. And while people have typically heard that you need vitamin D to absorb calcium, the relationship is actually a little more nuanced (in a good way, we're not talking about an on-again-off-again ex here) than that.*

Here's what to know about how vitamin D and calcium work together in your body—and why it's so important to get enough of the sunshine vitamin if you want to maintain healthy bones for life.*

In its active form in the body (called calcitriol), vitamin D is actually a hormone (how cool is that?) and works to maintain proper levels of calcium2 circulating in the body needed to mineralize bones, facilitate muscle contraction, allow blood vessels to dilate, support hormone secretion, and maintain proper nerve signaling.*

Because vitamin D plays such an important role in regulating how much calcium the body has available to use, bone health can pay the price when you fall short on the sunshine vitamin.* "Even if you're taking in enough calcium, it is ineffective if you're deficient in vitamin D,"* Tafur notes.

In fact, by limiting active calcium absorption, vitamin D deficiency significantly affects bone metabolism3, the continuous cycle through which bones turn over and grow (lay down mineral architecture). Over time, this can contribute to suboptimal bone health4.*

In order for vitamin D and calcium's relationship to function properly, it's important to maintain a balanced intake of both nutrients, says Tafur.* And as Ferira points out, "calcium is one of the most common mineral gaps in our diet, with close to 40% of American adults5 failing to consume adequate amounts from diet alone."

While dairy is one of the richest and most bioavailable sources of calcium, luckily for nondairy eaters, you can score calcium from a variety of leafy greens—as well as broccoli and salmon. And a targeted supplement is prudent for some folks to ensure they meet daily calcium needs.* And don't forget, vitamin D is pretty darn hard to get in ample amounts through food, though you'll find some in fatty fish, so the case for daily D3 supplementation is robust.*

While getting ample calcium (adults need 1,000 to 1,200 milligrams per day6) is important for health for a variety of reasons, you also need ample vitamin D daily to support a proper balance of calcium in the body.* Most people need a minimum of 3,000 IU of vitamin D3 per day to simply avoid vitamin D insufficiency, but 5,000 IU of D3 daily may be the ideal to achieve and maintain vitamin D sufficiency throughout life.*