Raphael Stevens

It seems that we’re always chasing the fountain of youth (not to mention, spending a pretty penny doing so)—be it an anti-aging cream, the latest cosmetic treatment, a supplement, or fashion styling hacks. But vanity aside, we all want to improve our longevity so we can live the longest, healthiest, most fulfilling life possible, right? While the jury’s still out on anti-aging creams, science says there are factors that can determine longevity.
We actually have two ages: a chronological age determined by when you were born, and a biological age, or the age at which your body functions. And your biological age may be younger or older than the age displayed on your driver’s license. Translation: You could be 30 chronologically, but have a biological age of 24 and have a lower mortality risk. But wait, there’s more good news: A recent study suggests that by taking vitamin D, we may be able to slow down the aging process–namely reverse biological age by a year–and promote longevity. Ahead, experts break down biological age and all the details you need to know about supplementing with vitamin D. 
 

In this article

 
What is biological age?
Your biological age takes into account a number of biological and physiological development factors other than just the day you were born, such as genetics, lifestyle, nutrition, and diseases. “Biological age represents the actual age of our cells, tissues, and organs, as determined by their biochemical state and function,” explained Dr. Xiaojing Yang, Group Leader of Epigenetics at myDNAge. “Our core area of focus is epigenetics, which studies how our lifestyles and environment can affect the way our genes work and express themselves. This plays a crucial role in determining your rate of biological aging and, in turn, impacts your body’s overall longevity and health span. Using specific DNA methylation biomarkers, we can calculate a person’s biological age.”
In other words, biological age is the rate at which you’re aging physically. And your behaviors—diet, exercise, and sleep (or lack thereof)—and exposure to environmental toxins (think: air pollution and chemicals) can affect your epigenetic makeup, determining whether you take years off your biological age or increase it. The main takeaway? “What we’ve learned now is we can literally reprogram our epigenome and reverse biological age at any age,” Dr. Mark Hyman, a leading expert in functional medicine, explained via The Cut. 
So how do you determine your biological age? The most accurate assessment is looking into your epigenetic data using DNA samples from your saliva, blood, or urine. And thanks to a new wave of companies offering at-home tests that reveal your “magic number,” it’s never been easier. For more information on testing your biological age, speak to your doctor on what testing is best for you.

How supplementing vitamin D can affect your biological age
Approximately 35% of adults in the United States have vitamin D deficiency, and based on a recent study, those people may be missing out on preventing accelerated aging: it found that people with low vitamin D in their blood were “biologically older” and had chromosomes (AKA the structures that organize DNA) that appeared older than people with adequate vitamin D levels (30-100 ng/mL).
Dr. William Li, a medical doctor and New York Times bestselling author of Eat to Beat Your Diet: Burn Fat, Heal Your Metabolism, and Live Longer, explained why: “Vitamin D is responsible for many functions in the body that slow biological aging, such as lowering inflammation, preventing oxidative stress, supporting immune function, improving bone strength, and slowing the shrinking of telomeres, which are the protective caps defending our DNA. Supplementing vitamin D adds to the body’s own control of these features of biological aging, although the exact mechanism is still being researched.”

What you need to know about supplementing with vitamin D
 
What dosage should I take?
There’s no one-size-fits-all dosage and frequency recommendation for taking vitamin D; they depend on many factors, such as your individual needs and environment. “Knowing how much vitamin D to take can be a challenge,” conveyed Dr. Arielle Levitan, a board-certified internal medicine physician. “Most of us are deficient if we do not take some vitamin D supplementation, but knowing a safe amount to take requires some expertise. Needs can vary based on factors including where you live (sun exposure matters), skin color, health conditions, and body weight.” While Dr. Levitan noted that a typical daily dose may range between 800 and 2000 IUs, it is best to determine your daily vitamin D needs by getting your levels tested and working with your physician to examine your diet, lifestyle, and health conditions.

When should I take it?

“Most doctors recommend taking vitamin D supplement with a meal to help the body absorb the vitamin,” Dr. Li affirmed. “Vitamin D is fat-soluble, but it’s not necessary to eat [it with] fatty food for it to be absorbed.” For that reason, look for a vitamin D supplement that contains fat (such as MCT, fish oil, etc.). While there’s no scientific evidence that proves whether taking vitamin D at night or in the morning is more effective, some reports claim supplementing with it at nighttime may interfere with sleep. Bottom line: Take vitamin D alongside a meal and make it a part of your routine consistently—whatever time of day works best for you.

Not all types of vitamin D are created equal. “Vitamin D should always be taken in the form of vitamin D3, which is more easily used by the body than Vitamin D2,” expressed Chante Wiegand, a naturopathic doctor and director of research and development at The Synergy Company. “Vitamin D3 should also always be taken with vitamin K2 to support optimal calcium absorption and bone health. While vitamin D ensures that calcium is properly absorbed, vitamin K makes sure the calcium is integrated into our bones.” 
 
Is it possible to take too much?

When it comes to vitamin D, you can have too much of a good thing. “Most vitamin D overdoses come from taking too many supplements, not from excess sun exposure or a vitamin D-rich diet,” Dr. Yang commented. “That’s why it matters to speak with your physician to determine the right dosage to take, to prevent any side effects such as kidney damage.” 
Wiegand pointed out that it would take consistent supplementation of vitamin D at very high amounts to reach unsafe levels, but it is possible. The signs to look out for? “Very high levels of vitamin D in your blood (greater than 375 mol/L or 150 ng/mL) can cause nausea, vomiting, muscle weakness, confusion, pain, loss of appetite, dehydration, excessive urination and thirst, and kidney stones,” she explained. 

 
Should anyone not take vitamin D?

“People who have kidney disease, including kidney stones, and those who have high blood levels of calcium or phosphate should not take vitamin D,” Dr. Li attested. “Some medications including statins and the heart drug digoxin can have potential interacts with vitamin D.” 

 
Shop our picks

 
Please consult a doctor before beginning any treatments. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical or mental health condition. Never disregard professional medical advice or delay in seeking it because of something you have read in this article.

8 Signs Your Probiotics Are Working More