Vitamin D needs are more nuanced than you might think. As mbg’s director of scientific affairs Ashley Jordan Ferira, Ph.D., RDN, explains: “The question of daily vitamin D needs is directly informed by your vitamin D status, measured via serum 25-hydroxyvitamin D from a blood test, or for short, 25(OH)D.”
The National Academies recommend a cutoff of 20 ng/ml for sufficiency, while The Endocrine Society more recently vetted the science and recommended a 30 ng/ml cutoff. As Ferira expounds, “to be clear, these cut points are numbers to avoid. In other words, you want to exceed 30 ng/ml daily for most of your life to reap the full benefits of vitamin D for health.”* In fact, a vitamin D supplement less than 20 or 30 ng/ml is associated with suboptimal bone density (not something to mess with).
To support your personal health, you’ll want to get familiar with your 25(OH)D levels, which means asking your health care provider for this simple blood test66. This is the clinical measure of your whole-body vitamin D status—and necessary information if you want to track your baseline status and watch how optimizing your vitamin D intake makes a significant impact.*
Brittany Henderson, M.D., a board-certified endocrinologist who specializes in hormones (including vitamin D) in her clinical practice, shares that “achieving optimal serum 25(OH)D levels in the 50+ ng/ml range is imperative for immune health, bone health, and more.”*
Now, here’s where things get interesting: Research shows that 100 IU of vitamin D3 (which is the body’s preferred form) per day raises 25(OH)D levels in the average (healthy weight) adult by 1 ng/ml77. So, if you want to hit 50 ng/ml, 1,000 or 2,000 IU of vitamin D per day won’t get you there; in fact, they won’t even get you close. Based on this science, you’d need closer to 5,000 IU per day to reach the optimal range.*
