Dr. John Day, Cardiologist

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The Right Way to Get Vitamin D

“Did your labs come back OK?” my wife Jane asked.

“Yeah,” I replied.  “Everything was what I expected except for my low vitamin D level.”

“What do you do when your vitamin D levels are low?”  Jane asked.

In this article I am going to share with you the latest research on vitamin D, the right and wrong ways to get vitamin D, and the ways in which I am working to get my vitamin D levels up.

Why Does Vitamin D Matter?

Since the childhood bone disease, rickets, was first described in 1650, researchers have long known about a crucial element that was needed for healthy bones. However, it would not be until 1918 that vitamin D was finally discovered.

The fascinating thing is that over the last decade or two we have discovered that not only are low levels of vitamin D associated with bone disease but that it is also linked to a myriad of other problems.  For example, low vitamin D levels are also commonly seen in people who are obese, have high blood pressure, are struggling with diabetes, or have high cholesterol.

Vitamin D and Heart Disease

In addition to the role of vitamin D for healthy bones, vitamin D may prevent cardiovascular disease.  This is especially important given that 74% of Americans are deficient in vitamin D.

For decades now, we have known that heart attacks tend to occur more often in people who don’t get much access to the sun like during the winter months and in geographic areas closer to either the North or South Pole.  In addition, countless studies have shown that heart disease is much more likely to occur in people with low vitamin D levels.

The Chicken or the Egg Conundrum

What we don’t know is whether low vitamin D caused the weight gain, diabetes, high blood pressure, high cholesterol, and heart attacks or whether these medical conditions caused vitamin D levels to drop.  In other words, did vitamin D cause all of these bad things to happen or are low vitamin D levels just a marker of someone with a lot of medical problems?

What is the Ideal Vitamin D Level?

At my hospital, the “normal” range for 25-hydroxyvitamin D levels is 30-80 ng/mL.  As my vitamin D level came back at 25 ng/mL, I was clearly deficient according to these levels.  Is this something that I need to worry about?

As a cardiologist, I am naturally interested in what are the optimal vitamin D levels for health and cardiac function.  As I have reviewed the scientific literature, the best study looking at vitamin D levels, in relationship to heart disease and longevity, is the NHANES III Study.

In the Third National Health and Nutritional Examination Survey (NHANES III Study), which involved 13,331 people, researchers found that a 25-hydroxyvitamin D level below 18 ng/mL or above 50 ng/mL was associated with cardiovascular disease and premature death.  Other studies have shown a similar vitamin D “sweet spot” usually somewhere between 30 and 50 ng/mL which is slightly lower the normal range of my hospital and what has been traditionally recommended.

Atrial Fibrillation and Vitamin D

As atrial fibrillation is the most common heart rhythm abnormality, and it is one of the leading causes of stroke, our team was very interested in looking at whether vitamin D played any role in atrial fibrillation.  In our study of 132,000 patients at Intermountain Healthcare, we found that even low levels of vitamin D (less than 20 ng/mL) had no increased risk of atrial fibrillation.  In contrast, people who took supplements to get their vitamin D levels above 100 ng/mL were 2.5 times more likely to develop atrial fibrillation.  Thus, our study showed that unless you took too much vitamin D, in the form of supplements, there was little link between vitamin D and atrial fibrillation.

What is the Right Way to Get Vitamin D?

The very best way to get the right amount of this critical vitamin is the way nature intended, namely through food and time spent outside.  In fact, nature even created a way whereby we can get enough vitamin D during the warmer months to get us safely through the winter.

For example, one study showed that it takes two months for vitamin D levels to drop after you have been outside in the sun.  This is because vitamin D is a fat soluble vitamin that is stored in fat.  This is nature’s way of protecting our vitamin D levels during the winter.

Studies suggest that our vitamin D levels are, for the most part, determined by how much time we spend outdoors.  As most people rarely get outside, perhaps this could explain why 74% of Americans are vitamin D deficient.

At the time my vitamin D level was checked, like most physicians, I spent most of my time inside of hospitals treating patients.  While I am still busy in my cardiology practice, I now make it a priority to get outside whenever possible.

Do Vitamin D Supplements Prevent Osteoporosis?

Many older women take calcium and vitamin D supplements to prevent osteoporosis.  Unfortunately, two recent large studies, both published in the prestigious British Medical Journal, challenge this long-held recommendation.  Unfortunately, both studies failed to show any benefit in improving bone mineral density or preventing fractures.

Do Vitamin D Supplements Prevent Heart Disease?

As with osteoporosis, vitamin D supplements have proven disappointing when it comes to preventing heart disease.  Paradoxically, people with the lowest levels of vitamin D are at the highest risk of heart disease but yet raising vitamin D levels with supplements have not been shown to help.

Do Vitamin D Supplements Prevent Cancer?

As with bone and cardiovascular disease, the same is true with cancer.  For example, people with low levels of vitamin D are much more likely to suffer from cancer.  However, giving vitamin D supplements have not decreased their cancer risk.

What Should You Do if Your Doctor has Prescribed Vitamin D?

Even though studies have not shown any clear benefit from vitamin D supplementation, if your vitamin D levels are low there may still be a role for supplementation.  As with any doctor prescribed medication or supplement, never stop something that has been prescribed without speaking with your doctor first.

What is the Right Way to Get Vitamin D?

As you can probably tell from this article, the right way to get vitamin D is to spend more time outside.  Of course, you have to be sun smart to minimize your risk of skin cancer.

For example, just 15 minutes of summer sun at mid day can provide you with a dose of vitamin D ranging from 10,000 to 25,000 IU depending on skin color (the vitamin D dose is lower from the sun in people with darker skin), cloud cover, elevation, and whether there is a reflective surface like water.

I should point out that clothing and sunscreen will block vitamin D absorption.  Also, the more skin that is exposed the higher the dose of vitamin D you will get from the sun.

The best time for the ultraviolet B rays and vitamin D production is somewhere between 10 am and 4 pm from April to October.  In contrast, ultraviolet A rays tend to dominate earlier or later in the day.

While too much ultraviolet B rays can cause sunburns, too much ultraviolet A rays can cause skin aging and wrinkling.  Both forms of ultraviolet light can cause skin cancer.

If you live closer to the Earth’s poles, like anything north of Los Angeles in the Northern Hemisphere, you probably will not get much vitamin D from the sun during the winter months unless you do the vitamin D sun “hack” that I describe below.  For people living far from the equator, you will need more vitamin D containing foods when the weather turns cold.

The Best Food Sources of Vitamin D

The very best food source of vitamin D is salmon.  Just a 4-ounce serving of salmon (158 calories) will provide you with 128% of the vitamin D you need for the day.  Other good food sources of vitamin D include sardines, tuna, milk, eggs, and mushrooms.

Vitamin K2: The Missing Link

We can’t just focus on vitamin D.  It is important to realize that vitamin D works in concert with calcium, vitamin K2, and vitamin A to make sure everything in the body is working correctly.

Of these, perhaps the most important may be vitamin K2.  The role of vitamin K2 is to keep calcium out of your arteries, where it can cause heart disease, and instead put it back in your bones.

Natto, Japan, Osteoporosis, and Heart Disease

A diet high in vitamin K2 may explain why the Japanese have extremely low rates of bone fractures despite eating minimal dairy and calcium.  For example, natto, or fermented soy beans, is a delicacy in Japan.  No other food comes anywhere close to comparing to natto when it comes to vitamin K2 content.

While natto tastes disgusting to most Westerners, I have actually learned to tolerate natto and have a tablespoon every morning.  Natto is something you can buy at most Asian grocery stores or you can even buy it online where they ship it to you in refrigerated boxes.

The Calcium Paradox

In addition to strong bones, studies suggest that vitamin K2 may also prevent heart attacks.  Vitamin K2 may be the answer to the “Calcium Paradox” wherein many older people suffer from lack of calcium in their bones (osteoporosis) but yet have too much calcium in the arteries of their heart (coronary artery disease).

How Do You Get More Vitamin K2?

If you cannot stand the taste of natto, how else can you get vitamin K2?  First of all, eat your greens.  Green leafy vegetables are very high in vitamin K1 which can be converted to vitamin K2 by your body.  To learn more about which foods contain vitamin K2, please read my article “9 Signs You May Have Vitamin K2 Deficiency.”

Warfarin, Osteoporosis, and Coronary Artery Calcification

I should point out that the people most at risk for vitamin K2 deficiency are those people taking the blood thinner warfarin (also known as Coumadin).  Warfarin blocks vitamin K and any attempts by you to eat more vitamin K1 or vitamin K2 foods will block this blood thinner.

Studies have shown that people taking warfarin are at higher risk for low bone mineral density and vitamin D as well as at increased risk for coronary artery calcification.  Fortunately, for most people, there are now new blood thinners that are much safer than warfarin.  If you or a loved one are still taking warfarin, speak with your doctor about switching to one of the safer new blood thinners that don’t block vitamin K.

The Wrong Way to Get Vitamin D

As you have probably guessed, the wrong way to get vitamin D is to just blindly take supplements without even first knowing your vitamin D levels.  The problem with supplements is that your body cannot control for toxicity.

In other words, if you take too much vitamin D the excess is just stored in your fat cells and toxicity can occur.  From our research, vitamin D toxicity can cause a dangerous heart condition called atrial fibrillation which can lead to strokes.  Vitamin D toxicity can also lead to dangerous levels of calcium in your blood or kidney stones.

When vitamin D is taken naturally, like through the sun, the body can control levels so that toxicity does not develop.  Given that 74% of Americans are deficient in vitamin D, many people may require supplements at least during the winter months.  However, vitamin D supplements should only be taken under the direction of a physician, who can monitor vitamin D levels, and only after you have first tried natural ways to correct your vitamin D deficiency.

The 5 Right Ways to Get Vitamin D

1. Get Tested

Get tested now to see if you are one of the 74% of Americans who have low levels of vitamin D.  Surprisingly, many insurance companies will not cover this simple and cheap test unless you have osteoporosis.  If your insurance company will not cover a vitamin D test, you can either pay for one out of pocket or purchase a much cheaper home test kit on Amazon or through the Vitamin D Council for as little as $50.

2. Start Winter with Your Vitamin D Tank on Full

Fortunately, studies show that vitamin D levels don’t start to drop until about 2 months after you have spent some time outside in the sun.  Thus, if your vitamin D tank is “full” on November 1, then you can at least get through the end of the year without any deficiencies.

However, in order to keep the tank full until spring, you will need that January vacation to a sunny beach, eat a lot of vitamin D containing foods, or supplement.  Please remember to always be sun smart so that you don’t trade vitamin D deficiency for skin cancer.

3. Eat Foods High in Vitamin D in the Winter

Knowing that vitamin D levels will drop through the winter, focus on the foods which are naturally high in vitamin D like salmon, sardines, tuna, cow milk, eggs, or mushrooms.  Also, many alternative milks, and other foods, are fortified with vitamin D.

4. The Winter Vitamin D “Hack”

Contrary to conventional wisdom, it is still possible to extract some vitamin D from the sun during the winter even if you live north of Los Angeles in the Northern Hemisphere.  However, this may require you to be on the top of a mountain with your skin uncovered and snow on the ground to amplify the sunlight dose.

There are some apps that can help you calculate your vitamin D dose.  By simply entering your latitude, longitude, skin type, how much skin is exposed (not covered by clothing or sunscreen), time of the day, sky cover, altitude, and what kind of surface is below you, you can calculate how much sun you need for your daily vitamin D needs.

5. Supplement When All Else Fails

Supplements should only be “supplements” for what is needed when natural approaches fail. I like USP or GMP certified supplements to minimize your risk of contaminants.

A Contrarian View to Vitamin D

Perhaps the real problem to vitamin D deficiency and the increased risk of osteoporosis, heart disease, and cancer is that most people don’t spend enough time outside.  It could be that low vitamin D levels are really just a marker of someone that rarely gets out.  Given the myriad of health benefits that happen when people are outside, like more physical activity, less stress, and less depression, it could be that the missing link is more time in nature rather than another supplement.

What did I Do for My Low Vitamin D Level?

This is something I struggle with as I hate to put any drugs or supplements into my body unless it is absolutely critical.  My “compromise” for a documented vitamin D deficiency is to eat more wild salmon in the winter, cross country ski at high altitude in just shorts on sunny winter days, and take a low dose of a vitamin D supplement.  Hopefully this approach will help to keep my bones and heart strong.

What do you do to ensure you have enough vitamin D to get you through the winter months?  Please share your comments below for our community to read.