Six reasons why you’re still vitamin D deficient

Vitamin D is one of the absolute best supplements you can take to support your health and longevity. Unfortunately, a majority of Americans — nearly 80 percent to be exact — simply aren’t absorbing enough of it, even after taking daily supplements and spending time in the sun.

Why is this? I find the deficiency usually relates to one of these six reasons:

  1. Form of vitamin D

The form of vitamin D you take can also make a huge difference… and yet, many people don’t even realize there are different types of this vitamin.

For example, vitamin D2 is less “bioavailable” than D3 — meaning you absorb less of it in your GI tract. And efficient absorption is crucial, since this is how nutrients enter your bloodstream.

Speaking of which, recent findings show that vitamin D3 immediately goes to work in your GI tract, or microbiome — where trillions of healthy bacteria thrive. And as I’ve reported many times before, the healthier your gut bacteria, the better your overall health.

  1. Too-low dosages

Most doctors still don’t have a clue about how much supplementation it really takes to achieve optimal vitamin D blood levels. And supplementing with just 1,000 to 2,000 IU of vitamin D3 per day won’t help most people get there.

Especially if you live in Canada, the northeast U.S., the upper mid-west, or the Pacific Northwest, where the sun’s rays just aren’t strong enough most of the year (even when the sun is out) to activate your body’s natural production of vitamin D.

If you live in these particular regions, supplement with at least 4,000 to 7,000 IU daily to increase the vitamin D levels in your blood. I always recommend you take 10,000 IU (which is what I personally do every day). This higher dose of D is associated with protection against chronic diseases — such as Alzheimer’s, multiple sclerosis, cancer, depression, and heart disease.

  1. Following a low-fat diet

Vitamin D is a fat-soluble vitamin, meaning it requires fats in the diet in order to be absorbed properly. So, following a ridiculously unhealthy “low-fat” diet — which also means low protein and high carbs — is another reason you might not be absorbing enough fat-soluble vitamins.

Supplements with vitamin D3 must also contain some healthy fats so you can properly absorb the nutrient. Pay close attention to this, especially in those useless multi-vitamins. They often throw some vitamin D in along with the other laundry list of random vitamins and minerals.

However, these supplements fail to contain any fats, so you end up not absorbing what your body needs. This is yet another reason why daily multi-vitamin supplements are worthless. You simply can’t get everything you need in one little pill. Instead, decide what supplements are right for you and get the proper formulations from sources you can trust.

  1. Medical conditions

As I mentioned earlier, it’s crucial for your GI tract to properly absorb vitamin D. Chronic malabsorption in the gut can hinder this process, whether you’re aiming to get your D from a supplement or from food sources. (Chronic malabsorption can also affect your absorption of other vitamins too, like B vitamins.)

Fat absorption is another problem. If your body doesn’t absorb fat, you’ll also have a harder time absorbing a fat-soluble vitamin like vitamin D.

Medical conditions that cause poor nutrient and fat absorption include liver diseases, kidney diseases, celiac disease, Crohn’s disease, and cystic fibrosis. Gastric bypass surgery also results in poor absorption of fats, vitamins, and other nutrients for a lifetime.

Have your doctor do a standard blood test to check your overall levels for any red flags or markers of these diseases.

  1. Obesity

If you’re obese, fatty adipose tissue sucks up vitamin D, preventing it from going where it’s needed in the body.

To address two birds with one stone, cut both sugar and processed carbs from your diet. Your waistline will shrink, and your vitamin D blood levels should improve.

In order to ensure your efforts are effective, it’s important to get your vitamin D levels tested every six months.

  1. Medications

First of all, I strongly advise against the use of statin drugs. This cholesterol-lowering drug can drastically prevent you from achieving optimal vitamin D levels.

In my view, artificially lowering cholesterol is not optimal for your overall health. Plus, lower cholesterol levels thwarts the absorption of vitamin D. And vitamin D relies on cholesterol as a basic building block.

Other prescription drugs can deconstruct and transform vitamin D to an inactive form. Avoid any drugs containing calcitroic acid. These most commonly include anticonvulsants, steroids, antiviral medications, and anti-immune drugs for preventing tissue rejection (typically following an organ transplant).

What you can do today for more D

Like I said earlier, vitamin D helps prevent and reverse just about every disease. That’s all the more reason to start taking the simple, necessary steps needed to increase your levels — today.

So do yourself a huge favor and take action toward bettering your health. Get started with these three simple steps:

  1. Ask your doctor to check your vitamin D levels twice a year — once toward the end of winter and again toward the end of summer. Just ask for a simple blood test called the 25(OH)D (25-hydroxy vitamin D) test. (Optimal blood levels are between 50 and 75 nanomoles/Liter.)
  2. Spend 15 minutes a day in the sun without sunscreen, especially this time of year. You can add more time each day. When you’ll be outside longer, wear some protective clothing, a hat, and sunglasses.
  3. Last, supplement with 10,000 IU of vitamin D3 daily. You can now find this dose in a convenient, highly-absorbable liquid form together with the potent marine carotenoid, astaxanthin, for added benefits. (For more information, simply type “astaxanthin” into the top right search bar of my website,

Vitamin D3 is hands-down one of my favorite supplements. If you were to take only one supplement, this would absolutely be the one.

To learn more about vitamin D3 and its disease-fighting benefits, I encourage you to visit my website, where I’ve written about it for nearly seven years now. And if you have any questions in particular, feel free to send me an email at [email protected].


Leyla Muedin, Dr Ronald Hoffman, Intelligent Medicine, May 18, 2018.