How much vitamin D do you need? Sorry to say, it’s not such a simple answer—mainly because we are all unique individuals with unique vitamin D needs, inputs, and physiology. Yep, your response to vitamin D can vary depending on a variety of factors, including your age.
Specifically, you might need even more of the essential micronutrient as you grow older: Here’s how age plays a significant role and what you might want to change on your vitamin D journey.
How your age affects your vitamin D levels.
“As we age our cutaneous production, or the skin synthesis, goes down naturally,” mbg’s director of scientific affairs Ashley Jordan Ferira, Ph.D., RDN, says on the mindbodygreen podcast. That skin synthesis process is how we get vitamin D from the sun: The sunshine hits exposed skin and, after a few conversion steps, creates vitamin D3. As Ferira notes, this process simply slows as you grow older, so your skin doesn’t create as much of the sunshine vitamin.
There’s also an environmental factor at play: With age, you might not spend as much time outside or engage in outdoor activities, which decreases sun exposure (and, thus, leads to less vitamin D3 production via your skin). This combined with potential medication interactions is why, Ferira says, “Older age is a major vitamin D deficiency risk factor to be mindful of, for yourself and your loved ones.*”
And sunshine aside, there’s another way age is limiting our vitamin D potential. Ferira explains that, “when we’re older, conversion of the circulating 25(OH)D form of vitamin D to its doubly hydroxylated form—the active, hormone form—is blunted in the body. Thus, a sufficient daily dose of D3 is essential to overcome these age-related mechanics.”*
The fix here isn’t to just spend ample time baking under the sun: “Of course, there’s major risk to your skin with sun exposure over time,” Ferira adds. “And the sun is so variable due to so many factors.” In addition to season, time of day (angle of sun), time spent outdoors, your clothing, skin tone, latitude or distance from the equator, pollution exposure, and the angle hitting your skin can all affect how much vitamin D you actually get.
Getting enough vitamin D through food is not at all realistic (here’s why), so that leaves us with supplements. We should note: If you’re already providing your body with sufficient vitamin D3 (5,000 I.U. plus per day) from a high-quality D3 supplement (or from a combination of food, sunshine, and supplement), then you’re probably fine to begin with, even though your body naturally decreases cutaneous production as you age. You can know for sure by getting your 25(OH)D levels tested.
A slew of factors can affect your response to vitamin D—one of which is your age. Again, everyone is a unique individual, and you might be dealing with multiple factors here (body composition can affect your vitamin D status, too, for example). But by making sure you have enough vitamin D (via a high-quality D3 supplement), chances are you can overcome those personal nuances.*
If you are pregnant, breastfeeding, or taking medications, consult with your doctor before starting a supplement routine. It is always optimal to consult with a health care provider when considering what supplements are right for you.
