How to Optimize Your Vitamin D

While most people would probably benefit from a vitamin D3 supplement, it’s important to get your vitamin D level tested before you start supplementing. The reason for this is because you cannot rely on blanket dosing recommendations. The crucial factor here is your blood level, not the dose, as the dose you need is dependent on several individual factors, including your baseline blood level.

Data from GrassrootsHealth’s D*Action studies suggest the optimal level for health and disease prevention is between 60 ng/mL and 80 ng/mL, while the cutoff for sufficiency appears to be around 40 ng/mL. In Europe, the measurements you’re looking for are 150 to 200 nmol/L and 100 nmol/L respectively.

I’ve published a comprehensive vitamin D report in which I detail vitamin D’s mechanisms of action and how to ensure optimal levels. I recommend downloading and sharing that report with everyone you know. A quick summary of the key steps is as follows:

1. First, measure your vitamin D level — One of the easiest and most cost-effective ways of measuring your vitamin D level is to participate in the GrassrootsHealth’s personalized nutrition project, which includes a vitamin D testing kit.

   Once you know what your blood level is, you can assess the dose needed to maintain or improve your level. If you cannot get enough vitamin D from the sun (you can use the DMinder app to see how much vitamin D your body can make depending on your location and other individual factors), then you’ll need an oral supplement.

2. Assess your individualized vitamin D dosage — To do that, you can either use the chart below, or use GrassrootsHealth’s Vitamin D*calculator. To convert ng/mL into the European measurement (nmol/L), simply multiply the ng/mL measurement by 2.5. To calculate how much vitamin D you may be getting from regular sun exposure in addition to your supplemental intake, use the DMinder app.



3. Retest in three to six months — Lastly, you’ll need to remeasure your vitamin D level in three to six months, to evaluate how your sun exposure and/or supplement dose is working for you.

Take Your Vitamin D With Magnesium and K2

As detailed in “Magnesium and K2 Optimize Your Vitamin D Supplementation,” it’s strongly recommended to take magnesium and K2 concomitant with oral vitamin D. Data from nearly 3,000 individuals reveal you need 244% more oral vitamin D if you’re not also taking magnesium and vitamin K2.

What this means in practical terms is that if you take all three supplements in combination, you need far less oral vitamin D in order to achieve a healthy vitamin D level.