What nutrient insufficiency affects half the population, is almost never diagnosed, and has been linked to many cancers, high blood pressure, heart disease, diabetes, depression, fibromyalgia, chronic muscle pain, bone loss, and autoimmune diseases like multiple sclerosis?
What vitamin is almost totally absent from our food supply?
What vitamin is the hidden cause of so much suffering that is so easy to treat?
The answer to all of these questions is vitamin D—which actually isn’t even a vitamin, it’s a hormone synthesized in the skin from sun exposure, and activated in the liver and kidneys.
As a Functional Medicine doctor, my focus is to help the body get what it needs to function optimally, not just function. In my decades of practice, I’ve become increasingly impressed and fascinated by the role of vitamin D in creating optimal health.
Almost 70 percent of American kids aren’t getting enough vitamin D, and this puts them at higher risk of obesity, having lower levels of good cholesterol, and all those states of dis-ease I mentioned above.
Overall, 7.6 million, or 9 percent, of American children were vitamin D deficient, and another 50.8 million, or 61 percent, had insufficient levels in their blood.
Over the last 10 years, I have tested almost every patient in my practice for vitamin D deficiency, and I have been shocked by the results. What’s even more amazing is what happens when my patients’ vitamin D status reaches optimal levels. Having witnessed these changes, there’s no doubt in my mind: vitamin D is an incredible asset to your health—even more so, after seeing the impacts of the COVID-19 pandemic.
That is why in today’s blog I want to explain the importance of this essential vitamin and give you 6 tips on how to optimize your vitamin D levels.
I also want to provide some helpful information on how vitamin D relates to the coronavirus, and why it could be helpful for better outcomes against this pandemic. Let’s start with that.
Vitamin D, COVID-19, and Flu Season
We’re seeing a very intriguing correlation between vitamin D and COVID-19. One study showed 80% of 200 COVID patients at a hospital in Spain were deficient in vitamin D, with men having lower levels than women, and this was also linked to higher inflammatory blood markers which we know lead to an increased risk for chronic disease. There are other clinical examples that show low vitamin D status in those with COVID-19 leads to an increased severity of symptoms and a higher risk of death. We also already know that vitamin D supplementation can reduce the risk of acute respiratory tract infections and that it plays an important role in immune function, so it makes sense that we should be paying attention to it amidst this virus that is known to attack the respiratory system.
For this same reason, we want to keep our vitamin D levels in mind as we enter into cold and flu season, not only because it’s essential for the immune system but also because we have even less of it in the colder months as less time is spent outdoors in the sun.
Now let’s look at the massive impact vitamin D has on the health and function of every cell and gene in your body.
How Vitamin D Regulates Your Cells and Genes
Vitamin D has a huge impact on the health and function of your cells. It reduces cellular growth (which promotes cancer) and improves cell differentiation (which puts cells into an anti-cancer state). That makes vitamin D one of the most potent cancer inhibitors—and explains why vitamin D deficiency has been linked to colon, prostate, breast, and ovarian cancer.
But what’s even more fascinating is how vitamin D regulates and controls genes.
It acts on a cellular docking station, called a receptor, that then sends messages to our genes. That’s how vitamin D controls so many different functions—from preventing cancer to reducing inflammation, boosting mood, easing muscle aches and fibromyalgia, and building bones.
These are just a few examples of the power of vitamin D. When we don’t get enough it impacts every area of our biology, because it affects the way our cells and genes function.
Your body makes vitamin D when it’s exposed to sunlight. In fact, 80 to 100 percent of the vitamin D we need comes from the sun. The sun exposure that makes our skin a bit red (called 1 minimum erythemal dose) produces the equivalent of 10,000 to 25,000 international units (IU) of vitamin D in our bodies.
The problem is that most of us aren’t exposed to enough sunlight.
Overuse of sunscreen is one reason. While these products help protect against skin cancer, they also block a whopping 97 percent of your body’s vitamin D production.
If you live in a northern climate, you’re not getting enough sun (and therefore vitamin D), especially during winter. And you’re probably not eating enough of the few natural dietary sources of vitamin D: fatty wild fish like mackerel, herring, and cod liver oil.
Plus, aging skin produces less vitamin D—the average 70 year-old person creates only 25 percent of the vitamin D that a 20 year-old does. Skin color makes a difference, too. People with dark skin also produce less vitamin D. And I’ve seen very severe deficiencies in Orthodox Jews and Muslims who keep themselves covered all the time.
With all these causes of vitamin D deficiency, and how hard it is to get from diet alone, you can see why supplementing with enough of this vitamin is so important. Unfortunately, you aren’t really being told the right amount of vitamin D to take.
The government recommends 200 to 600 IU of vitamin D a day. This is the amount you need to prevent rickets, a disease caused by vitamin D deficiency. You’ll also notice this is much lower than the amount we get from the sun, but we don’t get a vitamin D overdose from the sun thanks to our bodies’ ability to regulate it.
The real question is: How much vitamin D do we need for OPTIMAL health? How much do we need to prevent autoimmune diseases, high blood pressure, fibromyalgia, depression, osteoporosis, and even cancer?
That’s going to differ from person to person. From my own clinical experience and taking into account the latest research on vitamin D, I’ve seen that people generally do well with blood levels of 25(OH)D between 30-100 ng/mL, but that the optimal range falls between 40-70 ng/mL. Conventional doctors usually use a reference range of 20-50 ng/mL (which is what the 200 to 600 IU recommendation I mentioned above is based on). That means people at 20 ng/mL aren’t considered deficient, but they aren’t reaping the full benefits of higher vitamin D levels. Your individual labs will dictate if, or how much, vitamin D supplementation you might need.
Our government currently recommends 50 mcg (2,000 IU) as the upper limit for vitamin D intake—but even that may not be high enough for our sun-deprived population! In countries where sun exposure provides the equivalent of 10,000 IU a day and people have vitamin D blood levels of 105 to 163 nmol/L, which may seem extremely high, autoimmune diseases (like multiple sclerosis, type 1 diabetes, inflammatory bowel disease, rheumatoid arthritis, and lupus) are uncommon.
Don’t be scared that amounts that high are toxic: One study of healthy young men receiving 10,000 IU of vitamin D for 20 weeks showed no toxicity.
Why Optimization Counts
Unless you’re spending all your time at the beach, eating 30 ounces of wild salmon a day, or downing 10 tablespoons of cod liver oil a day, supplementing with vitamin D is essential. The exact amount needed to get your blood levels to the optimal range (40-70 ng/mL) will vary depending on your age, how far north you live, how much time you spend in the sun, and even the time of the year. But once you reach optimal levels, you’ll be amazed at the results.
For example, one study found that vitamin D supplementation could reduce the risk of getting type 1 diabetes by 80 percent. In the Nurses’ Health Study (a study of more than 130,000 nurses over 3 decades), vitamin D supplementation reduced the risk of multiple sclerosis by 40 percent.
I’ve seen many patients with chronic muscle aches and pains and fibromyalgia who are vitamin D deficient—a phenomenon that’s been documented in studies. Their symptoms improve when they are treated with vitamin D.
Finally, vitamin D has been shown to help prevent and treat osteoporosis. In fact, it’s even more important than calcium. That’s because your body needs vitamin D to be able to properly absorb calcium. Without adequate levels of vitamin D, the intestine absorbs only 10 to 15 percent of dietary calcium.
Speaking of calcium, we can’t talk about the impacts of vitamin D on bone health without also addressing vitamin K. This nutrient was long underappreciated but is starting to get more of the attention it deserves.
Vitamin K and Vitamin D Work Synergistically
Vitamin K and vitamin D both have an important responsibility to regulate calcium. Specifically, vitamin D helps you absorb calcium effectively and maintain a proper balance of it between your bones and blood. Vitamin K activates a protein called osteocalcin, that helps calcium get into your bones and teeth, and it also activates something called the matrix GLA protein, that prevents calcium from building up in soft tissues like your organs. On its own, vitamin K is essential to the blood clotting process.
So, if we have enough or too much vitamin D without vitamin K, calcium may not be getting to the right place, and can even cause problems by accumulating somewhere it’s not supposed to be, like the kidneys or blood vessels.
Just as vitamin D occurs in different forms, with D3 being the effective form to supplement with, vitamin K exists in two forms: K1 and K2. K2 is the form thought to be most effective for supplementation.
The foods richest in vitamin K1 are green leafy vegetables, cruciferous veggies like cauliflower, cabbage, and Brussels sprouts, and K2 can be found in fermented foods like natto, and sauerkraut, and some animal sources like liver, egg yolks, and chicken. Our gut bacteria also produces vitamin K2, when we have a healthy microbiome and some dietary K1 is converted to K2 here as well.
Vitamins K and D are both fat-soluble, so it’s helpful to take any supplements with some form of fat to aid in absorption. The Adequate Intake (AI) of vitamin K for adult men is 120 mcg per day and 90 mcg for women. More research is needed, and emerging, on vitamin K, but the AI basically is the amount needed to prevent a deficiency. We may find different amounts in the future for optimal health like we have with vitamin D. Right now, I’d at least recommend if you’re taking a vitamin D3 supplement to look for one that also contains vitamin K2 for the most efficacy, and definitely take both if you take a calcium supplement.
Now, here is my advice for getting optimal levels of vitamin D:
- Get tested for 25(OH)D. The current ranges for “normal” are between 20 and 50 ng/mL. These might be fine if you want to prevent rickets—but NOT for optimal health. In that case, the range should be 40 to 70 ng/ml. In the future, we may raise this “optimal” level even higher.
- Take the right type of vitamin D. The only active form of vitamin D is vitamin D3 (cholecalciferol). Look for this type and take it with vitamin K2. Many vitamins and prescriptions of vitamin D have vitamin D2—which is not biologically active.
- Take the right amount of vitamin D. If you have a deficiency, you should correct it with 5,000 to 10,000 IU of vitamin D3 a day for 3 months—but only under a doctor’s supervision. For maintenance, take 2,000 to 4,000 IU a day of vitamin D3. Some people may need higher doses over the long run to maintain optimal levels because of differences in vitamin D receptors, living in northern latitudes, indoor living, or skin color.
- Monitor your vitamin D status until you are in the optimal range. If you are taking high doses (10,000 IU a day) your doctor must also check your calcium, phosphorous, and parathyroid hormone levels every 3 months.
- Remember that it takes up to 6 to 10 months to “fill up the tank” for vitamin D if you’re deficient. Once this occurs, you can lower the dose to the maintenance dose of 2,000 to 4,000 units a day.
- Try to eat dietary sources of vitamin D. These include:
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- Fish liver oils, such as cod liver oil: one tablespoon (15 ml) = 1,360 IU of vitamin D
- Cooked wild salmon, 3.5 ounces = 360 IU of vitamin D
- Cooked mackerel, 3.5 ounces = 345 IU of vitamin D
- Sardines, canned in oil, drained, 1.75 ounces = 250 IU of vitamin D
- One whole egg = 20 IU of vitamin D
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You can now see why I feel so passionately about vitamin D. This vitamin is critical for good health. Start aiming for optimal levels and watch how your health improves—I feel so strongly about the impacts of vitamin D and vitamin K that I even formulated my own, you can get it right here.