How to Optimize Your Vitamin D Levels for Maximum Athletic Performance & Longevity

Vitamin D is one of the most important things our body creates for our health, performance, and longevity. Despite that, many of us just don’t have enough of it. Our body typically makes Vitamin D using sunlight, but in the modern era we send our time increasingly indoors and even when we are outside, clothes block our skin from making optimal amounts. 

Why is Vitamin D so important? Well, for one thing it’s actually not a vitamin at all, but something much more crucial. Vitamin D is a hormone, and is involved in bodily processes ranging from calcium absorption to energy levels to athletic performance. 

Most of us here at The Ready State are concerned with athletic performance, so we’ll look at the role of Vitamin D there first. Maintaining optimal Vitamin D levels via supplementation (particularly during the winter months) has been shown to optimize muscle function. In one such study, ballet dancers experienced an 18% increase in isometric muscle strength over control, and in others, Vitamin D improved injury recovery, vertical jump height, muscle protein synthesis, and sprint times

Then there are the health benefits. Optimal Vitamin D protects against infectious disease, lowers your risk for both cancer and heart disease, prevents diabetes, lowers your risk for obesity, and protects against neuropsychiatric disorders.

It’s kind-of a big deal, but hey, you might think you don’t have this problem. After all, you’re an athlete! You spend plenty of time outside, and you don’t exhibit any issues with the things listed above. Surely many people are low in Vitamin D, but not you, right?

Maybe, but I wouldn’t bet on it. Overall, 41% of the U.S. population is Vitamin D deficient, with deficiency reaching as much as 81% in the African American population, and 69.2% among hispanics. I mention these other groups only to give you a tool. Those with darker skin will want to take more action towards optimizing their Vitamin D. 

Basically, the average person has a 50/50 chance of being deficient in Vitamin D, with those who have darker skin being as much as 80% likely to be too low in this hormone, and this is in general. 

At the time of this writing, we are entering into the winter months, when people are more likely to be indoors and covered by clothes, not to mention that the sun is out for fewer hours of the day. This is prime time for Vitamin D deficiencies, which means it’s also prime time for action steps against deficiencies. 

How to Optimize Your Vitamin D at Any Time of the Year

Now for the fun bits: how to actually increase and optimize your Vitamin D.

When it comes to optimizing your Vitamin D, the two most effective paths are sun exposure and supplementation. 

Before we address either path for increasing Vitamin D, first we need to understand what optimal Vitamin D levels are, and how to test and re-test so that you actually know if your methods are working, and so you can avoid Vitamin D toxicity. 

Test & Re-Test

To optimize your Vitamin D levels, start by testing. It’s best not to supplement with Vitamin D without first knowing what your levels already are, as it is possible (though unlikely) to have too much Vitamin D. Sun exposure doesn’t carry this risk, and maybe you have perfect access to sunlight year-round, but some people don’t create Vitamin D in response to sunlight (even if they do tan.)

Certain genetic factors can compound to cause you not to make Vitamin D. My go-to source for health information, the biohacker Ben Greenfield, has this very set of genetic factors, as do his children. Despite the fact he is outside all the time, his Vitamin D levels stay low unless he takes a Vitamin D supplement. 

Ben discovered this by getting extensive and expensive genetic testing, but you can do it for much cheaper by doing a simple set of Vitamin D blood tests and re-tests. 

So, whether you’ve got the best tan in your beach community or you barely go outside, start by testing. 

The Vitamin D test is a blood test, and most blood labs consider a value of 20ng/ml of Vitamin D or higher to be adequate. 

Vitamin D blood test

However, the Vitamin D Council and many other functional medicine sources believe you need at least 30ng/ml and up to 50ng/ml to be sufficient. One study on Vitamin D concluded that 30ng/ml was the most advantageous for protection against all studied conditions, and 36-48ng/ml was necessary for cancer prevention, 

I am not a doctor, and I cannot give medical advice, but based on the research, I personally aim for a Vitamin D result of 30ng/ml to 40ng/ml.

Note: If you ever see research or test ranges that say you need 60 to 140 or higher Vitamin D, this is most likely measured in nmol/L instead of ng/ml.  The unit nmol/L is more popular in research labs whereas most consumer blood tests measure in ng/ml. For the sake of reference, 30 to 56ng/ml is equivalent to 75 to 140nmol/L. 

So, our first step is to figure out our baseline by getting a Vitamin D blood test. Luckily, for at least the first test you can probably use health insurance to cover the cost. Vitamin D tests are standard on most yearly physicals, and knowledge of the importance of Vitamin D is so widespread that many doctors will test you on request. 

Once you have your test results, you can start a protocol using one or both of the methods in this article to increase your Vitamin D. 

I will suggest testing protocols for each method below, but personally I recommend starting by using only sunlight to increase your Vitamin D so you can discover whether your body creates Vitamin D in response to sunlight at all. 

For re-tests, if your doctor is not willing to retest you using your insurance, you can get Vitamin D tests directly by using This website allows you to get a Vitamin D blood test for $60 from a local blood lab. 

Optimizing Vitamin D Using the Sun

As mentioned earlier, the best first step to optimize your Vitamin D is to use sunlight. Sunlight is the primary mechanism by which humans and animals create Vitamin D, and we are evolved to get all of our Vitamin D needs from this source. 

The issue is that we are no longer spending most of our time outdoors like we would be if we still lived like our ancestors. 

However, if you have a Vitamin D deficiency, first see if you can correct it by getting more sunlight. You don’t need a lot either, there’s no need to turn yourself into a leather-hide beach bum to get your Vitamin D levels right.

Simply spend 20 minutes outside with as much skin exposed as you can, at least 3 times a week when the sun is out. The best time of day for this is between noon and 3 pm when the sun is highest in the sky, but if that is not an option, going outside when you can is fine.  

Woman standing outside in the sun

The big advantage of using the sun to increase your Vitamin D levels is that your body has stop mechanisms to prevent you from making too much Vitamin D. You are very unlikely to have too much Vitamin D if you are using sun exposure as your only source. 

My only caveat for using the sun is this: do not get sunburnt. It’s perfectly ok to tan, but do not stay outside so much that you get a sunburn. For someone who has very fair skin and does not tan, this means that 20 minutes a session is probably the most your body can handle.

Don’t use sunscreen either, or cover-up. For one thing, covered skin will not create Vitamin D, nor will that which is lathered in sunscreen, but furthermore, skin cancer rates have only increased since sunscreen began use, and many sunscreens have active ingredients which are neurotoxic.  

Beyond that, here are a few tactics for optimizing your sessions to create the most Vitamin D possible:

Tactic Number 1: Do It Nude

If you are getting your sun exposure in your backyard, frequent a nudist beach, or have very unorthodox neighbors, get completely naked during your sunning. 

There are studies dating back to the 1930s showing that genitalia are the most efficient area of the body at optimizing hormones in response to sunlight. This isn’t just for Vitamin D either. In men, sun exposure to the nether regions had the greatest positive impact on testosterone. 

If you can’t expose yourself this thoroughly, it is best to get sunlight to the skin on your body evenly and throughout your body, but in particular, your back creates the most Vitamin D (after your genitalia) in response to sunlight and your front torso creates the least. 

Tactic Number 2: Don’t Wear Sunglasses

Research by those such as John Ott focuses on the close relationship between our biology and light. We have many mechanisms that intertwine to react to light, and one of the primary mechanisms of interaction is that of our eyes. 

The direct mechanisms are still not fully understood, but correlation data suggests that the eyes send a signal to your skin to produce more melanin, the pigment that causes you to tan, in response to brighter sunlight. If you wear sunglasses you hamper this process. 

John Ott, author of Health and Light, believed in particular that sunglasses are a factor in poor health, and that they limited our bodies need to interact with light to keep our health optimal. It’s really not so far fetched when you remember that light is one of the oldest influencers on biology, and that organisms have evolved with light since life on earth began. 

So, another way to improve your body’s ability to make Vitamin D is to toss the shades. Don’t stare at the sun or anything, and if you go hiking in the snow or are outside for a long time on a bright day, feel free to use shades rather than squinting the whole time. I try to avoid using them but I’m no masochist. However, for a simple 20-minute session in the sun, you should be fine without them. 

Tactic 3: Mobilize

Finding something to do while you sun is a great help for passing the time. Well, 20 minutes is also a great amount of time to mobilize and take advantage of The Ready State routines. When you move or mobilize, you activate your lymphatic system which in turn helps optimize your hormones. 

I haven’t found any studies on the effect of movement and creating more Vitamin D, but it’s very likely that your body is more efficient at optimizing this hormone while you are moving. 

Grab a foam roller or a lacrosse ball and spend 20 minutes on one of The Ready State routines while you’re outside sunning. Not only will you get your Vitamin D but you’ll reap the many benefits of body maintenance that brought you to this site in the first place. 

In Summary, get your Vitamin D tested. If it is below 30ng/ml, you want to raise it past that. Start by adding 20 minutes of sunning, 3 times a week and more days if you can.

Ideally, do your sessions completely naked without sunglasses on, and use the time to mobilize and activate the lymphatic system. Get another Vitamin D test after 2 weeks of these sessions to see if it increased your Vitamin D. If it did, test every month until you reach your desired Vitamin D levels. 

If your progress stops or slows down, and it is impractical to add more time in the sun, add some Vitamin D supplementation which will be described in the next section. 

Optimizing Vitamin D Using Supplementation

Vitamin D supplement

If sunlight is inadequate, or you do not have access due to weather, lifestyle, or biology, then it’s time to use a Vitamin D supplement. 

When it comes to what kind of Vitamin D to use in a supplement, you should always use Vitamin D3, and you should always take it with a Vitamin K2 supplement. Here’s why:

Vitamin D3, as opposed to D2, is more effective at raising blood levels of Vitamin D. That’s why you should supplement with it, however, it’s really Vitamin K2 that we need to spend some time on. 

I’ve alluded to the idea that too much Vitamin D supplementation can be harmful. The reason for this is that too much Vitamin D supplementation can cause over-calcification within the body. Vitamin D3 in high doses is actually used as rat poison, and kills the rats when over-calcification causes kidney failure. 

Now, I’m not trying to scare you off. Rats are much smaller than humans, and like many things, the dose determines whether Vitamin D is harmful or helpful. 

However, Vitamin K2 is massively protective against over-calcification, so much so that many medical practices now recommend only supplementing Vitamin D3 with Vitamin K2 accompanying it. 

The Riordan Clinic recommends supplementing with 40mcg of Vitamin K2 for every 5000 to 10,000 units of Vitamin D3 supplemented. Personally, I only supplement with Thorne Vitamin D3 Vitamin K2 drops, as they are already blended at these ratios. 

Thorne (no affiliation at the time of this writing) is also one of the highest quality supplement companies on the market, with multiple certifications such as NSF safe-for-sport and advisors like Ben Greenfield and other top experts in the health and fitness field. 

So, how does one actually supplement with Vitamin D now that we know what kind to use?

To supplement with Vitamin D, first pick an amount to aim at. As mentioned earlier, I believe 30ng/ml to 40ng/ml is optimal, and according to another study, 30ng/ml to 40ng/ml may be the minimum to reduce risks for all-cause mortality, cancer, and disease. 

Next, let’s test. If you’ve already done testing to see if the sun is enough to increase your Vitamin D, simply use your recent test as your baseline. I assume that if you are considering supplementing, then using the sun has not helped or simply is not enough or not available. 

Once you know your starting Vitamin D blood levels, begin supplementing 4000IU/d with 40mcg-200mcg of Vitamin K2. The same study mentioned above determined that oral supplementation with 6000IU/d was required to reach blood levels of 30ng/ml for those living in Finland, and 4000IU/d was required to reach blood levels of 40ng/ml.

After 4 weeks, retest your Vitamin D levels. You probably won’t be at 40ng/ml yet, but some people are hypersensitive to Vitamin D supplementation and this is why I suggest retesting after a mere two weeks. 

Adverse health effects were not observed below 56ng/ml blood levels of Vitamin D, so you have a pretty wide safety net if you are aiming for levels between 30ng/ml and 40ng/ml.

If your Vitamin D levels are rising, continue supplementing and testing once a month until your blood levels are between 30ng/ml and 40ng/ml. 

Once you reach your desired levels, drop your supplementation down to 5000IU/d for a month. Your goal is to find a protocol that will keep your vitamin D levels stable. If your levels maintain, then go ahead and keep using 5000IU/d as your regular supplement protocol. If your levels are still rising, then lower your dose by 400IU/d. If they are now lowering, then raise by 400/IU/d. 

Conclusion & Creating Your Personal Regimen

The ideal protocol is to get all your Vitamin D from the sun, but even if you make adequate vitamin D from sun exposure, you’ll likely become deficient during winter months or if you can’t get outside due to your schedule. 

This is why I personally have a combined protocol. During winter months, I supplement with  6000IU/d to 8000IU/d daily with 150mcg of Vitamin K2 to maintain my Vitamin D levels, testing every 3 months. If I test deficient, I supplement with 10,000IU/d to 15,000IU/d and 200mcg Vitamin K2 and test every month until my blood levels are between 30ng/ml and 40ng/ml.

During the spring, summer and fall, I drop my supplementation down to 4000IU/d and go outside for at least 20 minutes 3 to 5 times a week, still testing every 3 months if I’m maintaining, and every month if I’m trying to raise my levels. 

If I’m getting outside a high amount, such as on a summer vacation or I’m able to work outside, I find I can often drop my supplementation entirely and still maintain, but this is only if I’m really outside a ton.

The power of testing is that you can modify your Vitamin D protocol to fit your personal needs. 

I know I’ve warned about the dangers of supplementing with too much Vitamin D, but as long as you combine it with Vitamin K2, it’s very unlikely you’ll ever hurt yourself from Vitamin D supplementation. In one study, patients took 50,000IU/d up to 4 days a week, and yet no one experienced Vitamin D toxicity. 

However, without testing, you are essentially shooting in the dark, and may be missing out on massive benefits because your Vitamin D levels are still too low. 

As a Ready State athlete, the boons that come with good Vitamin D cannot be overlooked. From increasing muscle strength up to 20%, to recovering faster from injury, and even increasing power and speed, this is a powerful way to do it all. Furthermore, you’ll also protect yourself from diseases ranging from diabetes to cancer. 

You are now armed with everything you need to go out and optimize your own Vitamin D levels. 

Thank you for reading and good luck on your health, fitness, and life journeys. 

1 thoughts on “How to Optimize Your Vitamin D Levels for Maximum Athletic Performance & Longevity

  1. Avatar
    kimbily says:

    Vitamin D is one of the top micro’s that everyone should prioritise. However, I think the author may be seeking to throw the baby out with the bathwater in the section where he says to stop using sunscreen: Skin cancer is more deadly than low Vitamin D. Using a correlation of the modern use of sunscreen to cancer without outlining which risk is higher (or which cancer you risk) isn’t show much faith in your audience. Say what you like about alleged toxicity of sunscreen, but don’t leave out that the rise of cancer diagnosis is multi-factorial with the reason you singled out low on that list, if on it at all: improvements in diagnostic medicine, better public health campaigns to encourage people to get tested, better outcomes from treatment, longer lifespans to develop cancer, and not least that in the post-war period since the invention of sunscreen (and vacation-inventing unions) the west has had more leisure time than in human history to lounge outside in the sun.
    I’m sorry to discover the editorial standard of TRS’s blog is lower than the quality of its mobility instruction and probably will be skipping this section of the website until it improves.
    Regards, a sun-loving Australian who knows a thing or two about managing Vitamin D and skin cancer.

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