It’s no secret that Pittsburgh is not the sunniest of places to live. According to Current Results Weather and Science Facts, Pittsburgh annually receives 45% of sunshine. The number measures “the percentage of time between sunrise and sunset that sunshine reaches the ground.”

While we know that dark, dreary days affect our mood and mental health, making us want to curl up and stay in bed, the lack of sunshine here may also have implications for our physical health.

What is Vitamin D?

The National Institutes of Health describes vitamin D as a fat-soluble vitamin, meaning that it can be stored in our fat cells, unlike water-soluble ones that are excreted. Vitamin D can be acquired from the foods we eat and from sunshine. When ultraviolet rays from sunshine hit our skin, it triggers receptors in our skin to make vitamin D.
What Does Vitamin D Do?

Vitamin D is a bit of a jack-of-all-trades vitamin, helping throughout the body. It enables the body to absorb calcium to build strong bones, muscles to move, and the nervous system to send messages throughout the body, and it is essential for the immune systems, enabling it to fight off bacteria and viruses.

Why Are We Deficient?

With two ways of acquiring vitamin D, you’d think we’d have vitamin D in abundance, but for most of us, especially those who live in gloomier climates, that is not so. There are very few foods that are high in vitamin D. Fatty fish like tuna, salmon, and sardines, cod liver oil, and egg yolks have the most, but most people don’t eat enough of the those to be adequately supplied with the vitamin.

Sunshine is the second source for getting vitamin D. The National Institutes of Health says that factors such as “season, time of day, length of day, cloud cover, smog, skin melanin content, and sunscreen are among the factors that affect UV radiation exposure and vitamin D synthesis.”

How Do You Know If You Are Vitamin D Deficient?

Doctors don’t generally test for vitamin D deficiency, but there are blood tests available. Symptoms are the greatest indicators of vitamin D deficiency, and they include bone pain, fatigue, muscle aches, pain or weakness, and mood changes like depression.

How Much D Do We Need?

Essentially, the medical community is not sure how much vitamin D our bodies require. In a 2017 Mayo Clinic article the clinic “recommends that adults get at least the RDA of 600 IU. However, 1,000 to 2,000 IU per day of vitamin D from a supplement is generally safe, should help people achieve an adequate blood level of vitamin D, and may have additional health benefits. While there are no guidelines for checking your vitamin D blood level, it may be prudent in people with osteoporosis or certain other health conditions. Discuss with your health care provider if it may be beneficial to check your vitamin D level.”

Some Surprising Findings

With the onset of the COVID-19 pandemic, some surprising findings about vitamin D have come to light (pardon the pun.) Several studies have shown a correlation between vitamin D and being susceptible to the virus. You may have heard about Sweden adopting the “herd immunity” strategy for dealing with the virus rather than adopting social distancing. One startling finding thus far was published in The BMJ medical journal, and it reported that Somalis living in Sweden had a much higher rate of contracting the disease, with Swedish health authorities reporting that Somalis accounted for 6% of all the confirmed cases, which is 10 times more than their population share.

It may seem counter intuitive, but those with darker skin make less vitamin D from sunlight, and with many of the Somalis being Muslim and covering more of their skin, this has led some to think they have been hardest hit because they may be vitamin D deficient. Conversely, native Swedes tend to eat a lot of the vitamin D rich fatty fish, which would boost their vitamin D intake.

What About the Elderly & the Obese?

It is widely known that as we age, our bodies become less efficient at making vitamin D from sunlight, making the elderly more vulnerable to vitamin D deficiency. Perhaps that is one of the factors that explains why our older population was hit so hard in the pandemic. Vitamin D is fat soluble and would logically lead you to believe that overweight people would have a greater store of the vitamin to draw from, but that is not the case. A 2009 research study published in PLOS Medicine found that, “For every 10 percent increase in body-mass index (BMI), a person can expect to have 4.2 percent drop in blood levels of vitamin D. BMI is a measure of body fat that’s based on height and weight.” That may explain why the overweight had a higher risk factor.

How Many of Us Are Deficient?

It is estimated that 42% of Americans are vitamin D deficient and that number rises with age. A February 2020 study reported that, “the prevalence of patients with vitamin D deficiency is highest in the elderly, the obese patients, nursing home residents, and hospitalized patients.”

What Can We Do?

Unless you can persuade your doctor to write you a prescription for a trip to the tropics during the winter, you have two options. First, when it is sunny, try to take in some rays. You don’t need to lay out for hours and aim to look like George Hamilton. Exposing as much skin as possible for 10-30 minutes several times a week without sunscreen is all it takes.

Second, you can increase your consumption of vitamin D rich foods, but unless you’re into snacking on sardines, taking a vitamin D supplement can be beneficial. There are two types of vitamin D supplements, D2 and D3. Vitamin D2 must be prescribed by a physician and is commonly used for treating medical conditions like rickets, but D3 can be obtained over the counter and is more easily absorbed and is longer lasting in the body.

Don’t Over Do the D!

However, you don’t want to start gobbling vitamin D as you can take too much of it. Some symptoms of an over-abundance of vitamin D include nausea, constipation, confusion, slurring of words and stumbling, and weakness. As with any supplement, before you take it, you should always consult your physician.

More Study Needed

In conclusion, we all need vitamin D, and the bad news is many of us are deficient in it. It is clear that we need more medical studies to understand how vitamin D can boost our immune systems and ward of disease. The good news is that we can easily acquire vitamin D by seeking the sun, consuming vitamin-rich foods, and supplementing our diets.

Written by Janice Lane Palko