This Popular Vitamin D Supplement Might Lower Your Levels (Try This Instead)
It’s that time of the year again when we’re all thinking a little more about our vitamin D levels. Having optimal vitamin D levels plays a crucial role in immune health in addition to supporting bone health, sleep, and blood sugar balance (this vitamin does a lot in the body).
One of the best ways to get enough vitamin D is through a high-quality supplement. There are two main forms of vitamin D (D2 and D3). But a new study shows that supplementing with vitamin D2 actually depletes vitamin D3 in the body (potentially weakening the body’s immune defences). Here’s what you need to know.
The different forms of vitamin D
While vitamin D is, well, a vitamin, it’s actually considered a prohormone in the body. It’s a prohormone because the form of vitamin D you get from food, supplements, or sunshine isn’t fully active yet. It must first be converted in the body to become biologically useful.
The two main forms of vitamin D include:
- Vitamin D3 (cholecalciferol)is the form your body naturally produces when your skin is exposed to sunlight and is also found in animal-based foods like fatty fish, egg yolks, and meat.
- Vitamin D2 (ergocalciferol) comes mainly from UV-exposed mushrooms and fortified plant foods.
Supplements can provide either form, but once in the body, both D2 and D3 must be converted into 25-hydroxyvitamin D [25(OH)D], the main circulating form measured in blood tests to assess vitamin D status.
Both vitamin D2 and D3 have been shown to raise blood levels of 25(OH)D. However, vitamin D3 has long been known to be the more reliable and potent form of the vitamin, and it’s more recently been speculated that vitamin D2 may actually lower levels of vitamin D3 in the body, which is precisely what this study explored.
About the study
Researchers of this study analyzed results from 11 randomized controlled trials involving 655 individuals.
Participants took varying doses of vitamin D2, from daily doses around 300 IU to high weekly or monthly doses up to 50,000 IU. Researchers then measured blood levels of active vitamin D2, vitamin D3, and 25(OH)D (the sum of both forms) to see how D₂ supplementation influenced overall vitamin D status.
RELATED READ: Measure Your Vitamin D Levels At Home With These Tests
The downside of supplementing with vitamin D2
Results showed that supplementing with D2 significantly decreased active vitamin D3 in the body. Across trials, participants taking D2 had 9 to 18 nmol/L less active D3 in their systems than folks not taking any vitamin D
Vitamin D₃, on the other hand, consistently raises and sustains 25(OH)D₃ in the bloodstream. Researchers of this study concluded that “vitamin D3 should be the first line choice for supplementation”.
How to supplement
That means, if you’re looking for a vitamin D supplement (and many of us should be taking one as nearly 43% of U.S. adults have insufficient levels), make sure it's in the form of vitamin D3.
mindbodygreen’s vitamin D3 potency+ fits the bill. It provides 5,000 IU of vitamin D3 derived from algae and along with a trio of oils (avocado, flaxseed, and olive) to optimize absorption in just one daily gelcap.
It’s helped hundreds of customers raise stubbornly low levels of vitamin D to better support immune function, mood, muscle, and inflammatory responses.*
The takeaway
Not all vitamin D is created equal. And taking the wrong from vitamin D may have detrimental impacts on your vitamin D status and your body’s immune system. Always choose a supplement that provides an effective dose of vitamin D3 to reap the compound’s full benefits.