Vitamin D & K: Creating A Powerful Steroid for Your Bones & Hormone Health


Vitamin D3 & K2: Creating A Powerful Steroid for Your Bones & Hormone Health

Whether you’re an elite athlete, like to train recreationally a few times a week or just someone who stumbled on this article trying to live a healthier life, chances are you’re Vitamin D deficient. Low Vitamin D levels are extremely common in Western society and, even when levels aren’t clinically low, most people find themselves at a less-than-ideal spot on the spectrum.

“I would say 80-90 percent of people that get a blood test are coming up suboptimal,” IN3 Nutrition founder Jason Phillips said of Vitamin D. “One of my former colleagues was a paramedic and used to say that Vitamin D is so powerful at one point it could have been classified as a steroid.”

Yes, that’s right. Also known as the “sun vitamin”, Vitamin D regulates the functions of over 200 genes and is essential for growth and development. Being chronically low can compromise performance, recovery and even hormonal output.  Without enough Vitamin D, calcium —responsible for health bones, teeth and some brain functions—can’t be absorbed in the body.

“If you’re in a sport where you’re constantly cutting weight or just trying to significantly change your body composition, [Vitamin D] is something you definitely want to be paying attention to,” said Emmie Satrazemis, a board-certified sports RD and Trifecta System nutrition director. “If you are cutting calories and restricting your diet you are much more likely to have a deficiency.”

Vitamin D3 & K2: Creating A Powerful Steroid for Your Bones & Hormone Health

Low Vitamin D levels have also been linked to:

– Accelerated loss of muscle strength and mass as we age

-Lower testosterone levels

– Lower levels of immunity (immune system compromised)

– Higher risk of cancer and higher risk of blood pressure

– The development of neurological disorders and diabetes

So, just pop a few Vitamin D pills and you’re all set? Not exactly…

Vitamin D3 & K2: Creating A Powerful Steroid for Your Bones & Hormone Health

It can be hard in the fall and winter to absorb enough Vitamin D.


The best way to get optimal Vitamin D, where it’s most readily absorbed, is through the sun. As little as 15-20 minutes (without sunscreen) is a good dose. The problem is from October-March for those of us who live in places that aren’t warm and sunny year-round.

We preach fixing through  diet and exercise first, and supplementing only when to fill the gaps. But Vitamin D is technically not a vitamin or a dietary supplement. It’s a hormone. And it’s impossible to get enough through diet alone as Vitamin D is extremely rare in foods.

There is some in eggs, fish —much more in wild varieties than farmed— and mushrooms. But unless you’re chugging cod liver oil on a regular basis, chances are you aren’t in optimal Vitamin D standing.  It’s fortified in some cereals and milk, but again it’s not a natural source so absorption will be an issue.  And it’s probably not enough to give you optimal levels.


K2 to be specific. Long known to work together to balance calcium in your body, there’s emerging evidence that Vitamin D and K together can increase absorption and help your reach optimal serum levels without the risky of toxicity. Think of these two as a dynamic duo for your bones, hormonal health, immune system and overall longevity.

Taken together, studies suggest that optimal concentrations of both vitamin D and vitamin K are beneficial for bone and cardiovascular health as supported by genetic, molecular, cellular, and some human studies. Simply put, you taking extra vitamin D without extra vitamin K raises the risk of us depositing calcium in the arteries and soft tissue instead of where we really need it! Think of Vitamin K like a traffic cop directing Vitamin D to the right spots.

While we’ve listed the difficulty in getting D through foods, K2 can be found in hard cheeses and organ meats.

One study done in 2016 assessed the effects of vitamin D, vitamin K and calcium supplementation among 60 vitamin D deficient women with Polycystic Ovary Syndrome (PCOS), a common condition in which a woman experiences hormonal imbalances. The researchers assessed hormone levels, oxidative stress, antioxidant levels, among other outcomes.

They found that eight weeks of supplementation with 200 IU vitamin D, 90 μg vitamin K and 500 mg of calcium twice a day resulted in a significant decrease of oxidative stress and  serum-free testosterone, while total antioxidant capacity significantly increased compared to the placebo group. There were not enough study groups to determine if it was one supplement or the combination of all three, though the early research is encouraging on managing PCOS.

And the benefits aren’t just for females. A Japanese study in 2006 found rats with Vitamin K deficiency had lower testoerone and a separate trial done over five weeks showed the same thing from a different angle. That trial  showed a 70 percent increase in rats’ plasma testosterone after five weeks of daily doses of K2.

In the partnering of D3, another study found that giving patients with chronic renal diseases a combination of K2 and D3 significant slowed the arterial calcification (in a way that just Vitamin D did not). Not only does this pair together cut down on calcification problems —as mentioned earlier— but ensuring Vitamin D is uninhibited in our system frees it up to stimulate more testosterone. Numerous studies have also shown that the pair together can increase durability of our bones. 

Vitamin D3 & K2: Creating A Powerful Steroid for Your Bones & Hormone Health


Using a multi-vitamin to get adequate Vitamins D and K can be a problem. By the time enough vitamin D is consumed, you can reach toxic levels for other vitamins/minerals.

As with all supplements, quality should be the utmost priority when we are relying on non-food sources.

“What we need to consider most in general is the source, understand that a lot of vitamins are being made in labs and the way they are being made is not very pretty,” Phillips said.

“Do some research on it. In some labs the byproduct of what they are putting in capsules, is something that’s not regulated.  That’s something that gets ingested and absurd. So, it comes down to quality.”

Vitamin D and K are both fat soluble so you definitely don’t want to be just blindly loading up! Phillips and his team at IN3 –along with the Vitamin D Council– recommend 5,000 IUs as a safe and effective dose of D. As for K, 45 mcg is enough to lower prostrate cancer risk by 60 percent and help harness the potency of D. (Here’s a formula that has both.)

Even though blood testing isn’t rock solid, getting a reputable test to see where your levels are at is a great first step. Remember, you want to strive for the optimal range!

“I think [some of the research is] really promising. there’s quite a few supplement involved in bone strength, so it’s definitely a balance of a healthy diet and supplementing when you can’t get there,” Satrazemis said.  Theres definitely research that suggests you can absorb it more when you take K and D [together].”

But, like anything, there is more research to be done.

“I’d like to see a study on levels of absorption and how much is too much,” Phillips said. “That’s something that’s really yet to be done is how much do we have to take to absorb the levels that make the dose optimal?”


Vitamin D3 & K2: Creating A Powerful Steroid for Your Bones & Hormone Health

ADDITIONAL SOURCES (not linked in text):

You can find more information on the Nutritional Coaching Institute here.