Should you be worried about vitamin D deficiency?

I recently came across an article called “The Top Six Vitamins You Should Not Take.” Vitamin D was No. 6.

Of course, I found it in Forbes magazine, of all places. So I’m not surprised the author was grossly misinformed about nutrition and health. Getting your health advice from Forbes is like trying to get financial advice from your local doctors.

First of all, it’s just plain wrong. But it’s also just plain dangerous.

Almost every week, new research emerges about the importance of vitamin D for your mental and physical health–and I tell you about it right here.

Research shows that having enough vitamin D can help you prevent heart disease, cancer, dementia, and depression. Now, it’s also being shown to promote overall longevity. And a brand new study published in the Journal of Clinical Endocrinology and Metabolism found that older individuals who are vitamin D deficient also tend to have compromised immune function.

Plus, new research from my colleague Dr. Michael Holick at Boston University shows vitamin D helps regulate nearly 400 different genes throughout the body. So it acts like a hormone. As well as an essential nutrient.

I can only hope that most people don’t rely on the health advice found in a financial magazine. But Forbes is a trusted, mainstream magazine. And read by many otherwise clear-thinking readers. And it carries the illusion of sound advice. So that worries me.

With this kind of mainstream misinformation, it’s no wonder the U.S. currently faces an epidemic of vitamin D deficiency. And I’m not just talking about people with “insufficient” levels of vitamin D to prevent disease. Or people who don’t reach “optimal” levels for better health.

I am talking outright deficiency. The kind of nutritional deficiency that causes actual disease. (Of course, the government’s Recommended Daily Allowances were supposed to eliminate outright nutritional deficiencies in the 20th century. Clearly that didn’t happen.)

And I have not been exaggerating about the seriousness of the vitamin D problem in the U.S.

Three years ago, researchers wanted to find some definitive answers about vitamin D levels in this country. So they turned to the single largest and best source of health and nutrition information in the U.S.–the U.S. National Health and Nutrition Examination Survey (or NHANES).

They analyzed the NHANES data from 2005 to 2006 to determine vitamin D levels in 4,495 adult participants. They defined a vitamin D “deficiency” as a blood 25-hydroxyvitamin D level of less than 20 nanograms/milliliter (50 nanomoles/liter).

Overall, they found that nearly half (42 percent) of the participants had a vitamin D deficiency. African Americans had the highest rate at 82 percent. And Hispanics followed at a rate of 69 percent. Your skin color has a lot to do with your ability to generate vitamin D from sunlight. And people with darker skin tones require much more sun exposure to generate vitamin D on their own.

The researchers also found that vitamin D deficiency was significantly more common among:

  • men and women without college education
  • obese men and women
  • men and women with poor health status
  • men and women with high blood pressure
  • men and women who did not consume dairy products daily.

Bottom line?

Vitamin D deficiency is shockingly common in the U.S. today, no matter the superficial, ill-informed comments of some financial reporter.

Part of the problem stems from the government’s misplaced “war on saturated fats.” This steered many of us away from eating dairy, eggs and meat products. These foods are rich dietary sources of vitamin D. And they’re virtually the only sources available in our food supply for this essential nutrient.

But, clearly, another big part of the problem stems from “photophobia.” For decades, the mainstream government-industrial-medical complex scared us away from spending any time in the sun. And if you do spend time in the sun, they want you to slather on the “sunblock.”

Skin cancer is the big concern, right?

Well, we now know that vitamin D from sun exposure can actually help prevent all three types of skin cancers. As well as lower the risk of many other cancers. I’ll explain more about that cutting-edge research next week.

In any case, “photophobic” misinformation prevents people from getting adequate vitamin D from sun exposure. And that’s a shame. Spending even 15 minutes in the sun turns your skin into a vitamin D factory. Your skin will produce anywhere from 3,000 up to 20,000 IU from just sitting in the sun.

Of course, the exact numbers depend on many factors. Such as your skin tone, as I mentioned earlier. Your body composition. And your location on the map. (But remember, from November through March no amount of sun will activate vitamin D in your skin, if you live in the northern two-thirds of the U.S.)

As a whole, our country suffers from a misguided “war on the sun.” In Moby Dick, Captain Ahab says he, “would strike the sun if it insulted me.” Today, we have modern Ahabs hunting down the sun. This results in many “white whales” on the beaches, slathered in layers of ever-higher SPF level sunblock. Unfortunately, this blocks their ability to get enough vitamin D–even during summer. So we wind up with a vast percentage of the population deficient in vitamin D.

Everyone should take a high-quality vitamin D supplement of 5,000 IU every day. If you feel a cold coming on, you can probably decrease the duration and severity of symptoms by upping your dose to 10,000 or even 20,000 IU.

Also, make sure you know your numbers. Ask your doctor at your annual check-up to run a vitamin D blood test. There are two different blood tests for vitamin D. So be specific. And ask for the 25(OH)D test.

There are also home tests available. You administer the test at home and send away for the results. But I would steer you away from this option. Working with a trusted physician is a much better course. It is a big health problem. Despite what Forbes may think. And doctors are catching on.


1. “Prevalence and correlates of vitamin D deficiency in US adults,” Nutr Res 2011 Jan;31(1):48-54

2. “Vitamin D deficiencies impaired immune function of older adults,” J Clin Endocrinol Metab published online ahead of print 2/25/2014

3. “The Top Six Vitamins You Should Not Take,” Forbes magazine ( 1/13/2014