The ignored epidemic
I went to my primary care doctor for my annual checkup recently. I got a full physical, which included an EKG for my heart, breast exam, and a full blood workup. I had to wait for my blood test results. And I have to say, I was a bit nervous about a particular blood test result. But it’s probably not the one you think it is.
After about five days, my doctor called with my blood test results and everything was OK, except for my vitamin D level.
I’ve been struggling with vitamin D insufficiency for at least six years. Each time I’ve tested the results is just bordering on a deficiency. This time my vitamin D value was 11.6 Nanograms per milliliter. Sufficient (or average) ranges from 30 to 100 ng/ml.
Vitamin D is technically a misnomer. It’s not a vitamin at all, but instead a prohormone. This is because the body can produce vitamin D naturally. Vitamins like vitamin C or K must be absorbed through diet or supplements. But for the purpose of this article, we will continue to describe vitamin D as a vitamin.
Vitamin D is known as the sunshine vitamin because it is naturally produced when ultraviolet rays, specifically UVB, from the sun hit the skin. The skin has a cholesterol substance called provitamin D3 that reacts with UVB rays to form vitamin D3. It is absorbed into the body, going into the liver and then the kidney. Eventually, the body converts all the provitamin D3 it needs into vitamin D.
It is estimated that 50 to 90 percent of our vitamin D comes from the sun, which is good because vitamin D doesn’t naturally occur in many foods. It is most commonly fatty fish like salmon, trout and mackerel; egg yolks; and Portobello mushrooms. Several foods are fortified with vitamin D, which means vitamin D is added, including certain orange juice brands, milk, yogurt and some cereals.
This vitamin is vital for human growth and development. It helps maintain healthy teeth and bones, supports heart health, as well as regulates calcium and phosphorous absorption. It also protects against a bunch of diseases including type 1 diabetes, multiple sclerosis, and breast, pancreatic and colon cancer. Vitamin D deficiency has also been linked to obesity, high blood pressure, depression, fibromyalgia, osteoporosis, Alzheimer’s disease, stroke, autoimmune diseases like Lupus, birth defects, and periodontal disease.
Ok. We can all agree, getting some more vitamin D is well worth it, at least for me. Someone who knows they have low levels. But what does this have to do with you?
In 2010, Dr. Zahid Naeem authored a paper in the International Journal of Health Sciences entitled, “Vitamin D Deficiency – An Ignored Epidemic.” And he was right to call it that.
It is estimated a third of the world’s population may have low levels of vitamin D. This number is based on a review of 200 population-based vitamin D studies from 44 countries. Despite there being so many people possibly affected by this deficiency, you don’t see the World Health Organization drafting plans to eradicate this problem by 2050. Nor is it ranking as a major public health concern in the United States, where three-quarters of teens and adults lack this crucial vitamin.
I have no idea why those in charge of addressing public health issues on a policy level aren’t addressing public health issues on a policy level. But I can explain why so many people are vitamin D deficient.
Here are some factors that make obtaining vitamin D a challenge.
Factor #1: Melanin.
I know, how can something so good hurt me?
So here’s the problem – melanin is too good at its job.
As a quick refresher, melanin is the pigment that gives the human skin, hair, and eyes their color. It is also found in the brain and most internal organs. The darker the skin, the more melanin in the skin; the lighter the skin means less melanin. No matter your skin color, everyone has melanin. According to the American Academy of Dermatology, everyone has the same amount of cells that make melanin, but not everybody produces the same amount. So basically melanin deflects or absorbs ultraviolet rays from the sun. This helps to prevent skin cancer.
Herein lies the problem. Because melanin is blocking all those UVB rays, it is also reducing the amount of vitamin D your body produces. It is estimated that people with darker skin absorb 99 percent of UVB rays, which in turn decreases vitamin D production in the skin by 99 percent.
Factor #2: Aging
As we age, our body becomes less efficient at producing vitamin D from sun exposure. Research shows a 70-year-old makes four times less vitamin D from the sun than a 20-year-old.
Factor #3: Body fat
Vitamin D is fat-soluble, which means it is absorbed in fat globules (called chylomicrons) that travel through the lymphatic system of the small intestines and into the general blood circulation within the body. So the more body fat you have, the harder it is for your body to release vitamin D into your bloodstream. Studies show obese individuals have 50 percent less vitamin D absorption than non-obese people.
Factor #4: Location
Those living in temperate climates are more likely to be vitamin D deficient, compared to those living near the equator where vitamin D synthesis is more efficient. So people that live above the Mason-Dixon line are more likely to have vitamin D deficiency.
Factor #5: Food intolerance
So if you can’t get vitamin D from the sun, there are foods with it. But you might not eat those foods. Certain ethnic groups are more likely to suffer from vitamin D deficiency because of food intolerances. Approximately 90 percent of Asian Americans are lactose intolerant, so they probably don’t get the D from milk or yogurt.
As a note, this doesn’t mean you should go outside and sunbathe as these activities increase your risk of skin cancer and are generally inefficient. A study from the Skin Cancer Foundation found that the body stops producing vitamin D after five to ten minutes. Researchers, instead, recommend vitamin D tablets.