How to Fix a Vitamin D Deficiency to Get Stronger

Scientists recruited 37 sets of monozygotic twins between the ages of 18 and 40, presumably with varying degrees of creepiness, to participate in a randomized clinical trial to determine the specific effects of vitamin D supplementation.

It was a pretty simple clinical trial – one group received 2,000 IU of cholecalciferol (vitamin D3) each morning for 60 days, and the other group didn't.

Blood was drawn from each participant (after a 12-hour fast) before the supplementation began and again 60 days later.

Before-and-after isometric muscle strength was determined through dynamometry using a handgrip test and a scapular strength test. Before-and-after V02 max was ascertained using the same type of cardiopulmonary stress test doctors perform to determine heart and lung efficiency.

• The blood concentration of vitamin D in the study group (those taking the supplement) increased by 70%.
• The VO2 max of the twins in the study group increased by 28%.
• Muscle strength in the left hand of the study group increased by 18%. (Determining changes in the strength of the non-dominant hand is a much more accurate indicator of any changes in strength since the dominant hand is usually around 10% stronger than the non-dominant hand.)

All this good stuff led the researchers to write the obvious:

"Increasing the serum concentration of vitamin D to values above 50 ng/mL has beneficial effects on physical fitness, improving V02 max and increasing manual muscle strength."

Unfortunately, vitamin D's been typecast. She's had a recurring role in beefing up the immune system for so long that few people realize the breadth of her abilities.

Sure, it's recognized by those in the nutrition/health world that she also deftly handles the role of controlling calcium metabolism, but that's her "art house" film, seen or recognized by few. Similarly, as the study we've been analyzing makes clear, she also plays an important role in cardiopulmonary and muscle functions.

Consider what happens when we don't have enough vitamin D – aside from immunological impotence, we suffer muscle weakness, arterial thickening, myocardial hypertrophy, and hypertension.

Let's take it even further. If you've got poor cardiovascular health induced by a vitamin D deficiency, you're also prone to be more insulin resistant and, well, fatter, with an unenviable lipid profile.

However, as this study shows (along with several other studies), taking vitamin D3, above and beyond what the average person might ingest through fatty fish or mushrooms, can not only remedy the aforementioned health problems but make people better than they were.

You'd think that these effects would have been more widely known, but part of the problem might stem from two factors, the first having to do with what's defined as "normal" (20 ng/mL or above) levels of vitamin D and the woefully inadequate RDA for the vitamin (600 IU for male and female adults).

The concern has always been that too much vitamin D can cause a build-up of calcium in the blood, which could make the insides of your blood vessels and heart start to look like the interior of a White Castle. This generally doesn't happen, though, unless you're one of the rare individuals who suffers from hypoparathyroidism.

Second, many doctors, who spend about as much time studying nutrition as they do diseases of the taint, get apoplectic when your vitamin D levels rise much over 30 ng/mL. They worry about toxicity (since it's fat-soluble and gets stored in your plump parts) and the fact that, as is true with many things, more doesn't appear to be better.

But they're partially wrong on the former and totally wrong on the latter. Vitamin D is fat-soluble and can cause toxicity in prolonged large doses (hypercalcemia, vomiting, kidney problems, etc.), but it seems doses of up to 10,000 IU a day (the amount your body makes naturally after 30 minutes of sun exposure) are perfectly safe.

As far as "more not being better," several studies, including the one we've been discussing, have proven that generalization wrong. Most savvy nutritionists and biohackers now regard 50 ng/mL as the low bar of vitamin D status. Raising levels to that amount can confer remarkable resistance to many diseases and viruses, along with increased VO2 max and muscular strength.

So, after reading this, you might want to increase your vitamin D3 intake so that it goes above 50 ng/mL, or at least so it touches the rim. That hasn't been easy for most people.

A lot of the vitamin D present in the food you eat is bound up in the actual food and remains so after you eat it. Lots of things contribute to this: the physiochemical form of the vitamin D, the fatty acids and fibers in the food, the size of the food particles themselves, and the quantity of the vitamin itself.

Interactions between vitamin D and other fat-soluble nutrients might also be a factor, as well as a bunch of host-related issues (age, disease state, fed condition, genetics, obesity, etc.).

Then there's how you might prepare any vitamin-D-containing foods. Heat affects it. Light affects it. Moisture, oxygen exposure, and even storage conditions affect levels of vitamin D. That means that any vitamin-D containing foods that are boiled, pressure-cooked, Insta-Potted, baked, or air fried end up being vitamin-D compromised.

Add to that the fact that vitamin D needs its sidekick, magnesium, to make a formidable immune system. Ordinarily, that wouldn't be a problem, but it's estimated that up to 80% of the population is deficient in the mineral.

It's no freaking wonder that vitamin D deficiencies are rampant or why it's so hard to elevate levels. Still, next to regular but prudent sun exposure, supplementation is still the best solution to vitamin D deficiency. But I'm not talking about taking old-technology vitamin D supplements; they're prone to all the same previously mentioned manufacturing and absorption problems that food is.

The answer is microencapsulated vitamin D3. This form of the vitamin is manufactured by encapsulating vitamin D3 molecules in liposomes or solid lipid nanoparticles.

The vitamin then presents as tiny "beadlets" and is protected from moisture, oxidation, pH, temperature, and mechanical forces. The microencapsulated product is stable, water dispersible, and, most importantly, highly bioavailable.

Studies show that the effects of this form of vitamin D3 remain constant for up to 14 days, making it clearly superior to the conventional vitamin D3 supplements that comprise most of the market. Biotest, however, recognized the value of microencapsulated vitamin D3 and immediately incorporated it into its I-Well™ Immune Support product.

Each 3-capsule serving contains 5,000 IU of vitamin D3 (as cholecalciferol), along with 400 mg. of beta-1,3-glucan, 400 mg. of EGCG, and 400 mg. of solid lipid curcumin particles, each with its own immune-boosting properties.

You definitely need to incorporate it in your health and fitness armory, if not for your general health, to ensure optimal cardiorespiratory fitness and muscle strength.

1. Medeiros JFP et al. Association of Vitamin D Supplementation in Cardiorespiratory Fitness and Muscle Strength in Adult Twins: A Randomized Controlled Trial. Int J Sport Nutr Exerc Metab. 2022 Jan 1;32(1):2-7.