Does Your Vitamin D Status Yo-Yo Throughout The Year? Here's Why That's Bad

Vitamin D insufficiency and deficiency are rampant in this country. (In fact, almost half the population1 of the U.S. is insufficient and almost one-third are deficient2.)

Picture this: You test your vitamin D levels at the doctor and receive a serum 25(OH)D lab result (the biomarker for your vitamin D status) of less than 30 ng/ml, which means you're clinically insufficient. As a result, your doctor may recommend you take a D3 supplement daily (and the dose may be variable from one health care provider to another) or may prescribe 50,000 IU of vitamin D2 per week for eight to 12 weeks or so to bump you back up to the sufficient range.* Then, you get tested again, and—hooray!—your levels have zoomed above 30 ng/ml (or maybe you are just slightly above 30 ng/ml now). Your doctor sends you on your merry way, perhaps with no follow-up instructions, and you're all set...right? 

Sorry to say, this on-again-off-again approach to vitamin D is incredibly common. "I have heard about and witnessed this common pattern of temporary sufficiency or yo-yo-ing between vitamin D sufficiency and insufficiency (or deficiency, even) through the years from clients, family, friends, and strangers," Ferira explains. "It's why snapshots in time demonstrate that large proportions2₂—many millions of Americans—are clinically vitamin D deficient or insufficient."  

If you yo-yo in and out of suboptimal vitamin D status (or even swing into deficient states), you may never reach truly sufficient levels throughout your life span—which, in turn, has broad health implications for your bones, muscles, immunity, neurological function, cardiometabolic health, and more.* 

Take it from Ferira: "Vitamin D sufficiency doesn't just mean you're meeting a 25(OH)D level or cutoff," she says. "It means your bones, muscles, immune cells, brain, heart, liver, gut, reproductive organs, and many more cells, tissues, and organs have this critical nutrient available in adequate quantities to bind to vitamin D receptors and promote calcium and phosphorus balance, bone mineralization, muscle strength, immune function, cardiometabolic health, and more."* 

And to achieve consistently sufficient levels, again, requires daily maintenance—and daily supplementation is the best evidence-based way to ensure you have enough vitamin D every single day.* Food and sunshine don't exactly cut it (here's why), and prominent D experts and the latest research suggest 5,000 I.U. of D3 per day, which helps you hit an optimal 50 ng/ml level (and keep it there), is a truly effective dose.*