You can avoid getting “too much” vitamin D—despite what you’ve heard

I often discuss the importance of vitamin D. Research links optimal levels to a reduced risk of just about every chronic disease on the planet. Which is why I  suggest you supplement year-round with 10,000 IU daily of vitamin D3.

Of course, some so-called experts dither about getting “too much” of this critical vitamin. But, as I’ve explained before, this worry is complete nonsense. Plus, a new study has found that magnesium helps regulate vitamin D—making it possible to avoid the risk of an “overdose.”

I’ll tell you how much magnesium you need daily and which forms to avoid in a moment. But first, let’s take a closer look at that study…

New study finds magnesium regulates vitamin D

The new study, published in the American Journal of Clinical Nutrition, focused on the role of magnesium as part of the Personalized Prevention of Colorectal Cancer Trial.

Researchers randomly assigned participants to receive either a placebo or magnesium supplements. And for the magnesium group, researchers adjusted the daily dosage based on the participants’ normal dietary intake of calcium and magnesium at the study’s outset.

This kind of personalized approach in dosing represents a significant advancement beyond the blind, one-size-fits-all studies that have dominated the field of nutritional research for decades. And it seems to represent an encouraging new trend toward better science, as I recently pointed out.

As it turns out, magnesium supplementation helped regulate vitamin D levels…

In fact, they found that when initial vitamin D levels were insufficient (below 30 nanograms/mL), magnesium supplementation actually increased D levels! And in people with high vitamin D, magnesium was shown to balance those levels out.

I recommend keeping your vitamin D levels between 50 ng/mL and 75 ng/mL.

Three key takeaways about magnesium and vitamin D

So, the way I see it, there are some major things to keep in mind…

First, the study reinforces the fundamental concept that vitamins and minerals always work together to regulate metabolism.

Second, this study clearly illustrates that magnesium helps regulate blood levels of vitamin D. And the mainstream’s preoccupation with vitamin D “overdose” is really just another dangerous medical myth. So, you can stop worrying about taking “too much” of this critical vitamin, especially when most of our population is actually deficient.

Third, the study shows that supplementing with magnesium and vitamin D is essential to achieving optimal health. As I mentioned above, I recommend you supplement daily and year-round with 10,000 IU of vitamin D. You can now find vitamin D in a convenient liquid form, together with the potent marine carotenoid astaxanthin. (To learn about my personal recommendations, visit and search the “Shop” tab.)

You should also supplement year-round with 200 to 400 mg of magnesium daily, as nearly 80 percent of U.S. adults are deficient. Just make sure you take the right form.

You can also get magnesium from foods, such as:

  • Avocado
  • Beans
  • Cacao
  • Fish and meats
  • Green leafy vegetables
  • Nuts such as almonds, cashews, pecans, and walnuts
  • Pumpkin seeds
  • Seaweed

You can also increase your magnesium levels by enjoying a soothing Epsom salt bath.

Now, I know calcium supplements often get lumped into the conversation about magnesium and vitamin D. But as I often report, you should always get your calcium from foods, not supplements.

So, as we head deeper into spring, get outside in the sunshine every day for a few minutes to keep your vitamin D levels up. And you won’t need worry about “overdosing,” because your body has built-in mechanisms to naturally keep vitamin D at safe levels.

Of course, the attacks on vitamin D continue. So, next month, I’ll expose another three recent attempts that have been in the headlines.


“Magnesium status and supplementation influence vitamin D status and metabolism: results from a randomized trial.” The American Journal of Clinical Nutrition, 2018; 108(6): 1249–1258.