My College:
Health & Safety

D — The Sunshine Vitamin

MJ O'Leary

Summer has come to an end and all things fall are in full swing. The kids are “back” in school, temperatures have cooled, and the sun dances its way through our waking hours with less intensity each passing day.

The transition from summer to fall, and fall to winter, can have a profound impact on our health if we neglect to monitor the effect of seasonal change in our body.

When the glorious rays of the sun hit our skin, we manufacture vitamin D. D is responsible for the proper workings of hundreds of different pathways that control our mood, immune system and brain function. We have trillions of cells in our body and they ALL need vitamin D!

Small amounts of vitamin D can be found in food, although most vitamin D is made when an inactivate form of the nutrient is activated in your skin when exposed to sunlight. The sun has to be high in the sky for us to create the active form of vitamin D, and this only happens during the warmer months in many parts of the U.S.

Where we live may put us at risk of developing a D deficiency — an undesirable outcome!

The Health Benefits of Vitamin D

When discovered, D was thought to be a vitamin, thus the name. We now know that vitamin D is actually a hormone. In fact, it is one of only two hormones every single cell needs, making it essential for vibrant health.

Vitamin D has been show to:

Protect against heart attack and stroke

Low D levels are associated with a greater occurrence of heart attack and stroke. According to vitamin D researcher Dr. Michael Holick, vitamin D deficiency can raise your risk of heart attack by 50%.

Improve respiratory health

Vitamin D has a protective effect against upper-respiratory infections, and moms with higher D levels give birth to babies with a 40% lower risk of developing asthma.

Boost brain health

Vitamin D is essential for a healthy brain — low levels are linked to decreased memory and increased rates of neurological conditions. Low levels of vitamin D are also linked to a 14% increase in depression and a 50% increase in suicide rates.

Strengthen bones

Vitamin D helps the absorption of calcium, increases the strength of the skeletal system, and prevents the breakdown of bone.

Simply, vitamin D plays an essential role in disease prevention. Intensive care patients have almost three times the risk of death if vitamin D deficient, and studies have linked higher vitamin D levels with lowered mortality from all causes, including cancer. One study found women over 55 who raised their average serum level to 38 ng/ml lowered their risk of all invasive cancers by 77%.

Vitamin D and COVID-19

If your D level is below 20 ng/ml you are considered deficient. It's estimated that upwards of 40% of Americans fall into this category.  This deficiency has collided with the COVID-19 pandemic and quite possibly contributed to the number of COVID-19 deaths.

A University of Chicago study found that untreated vitamin D deficiency was associated with an increased risk for COVID-19 infection (please note this new medical research has not yet been peer-reviewed and therefore isn't being used to guide clinical practice). Another study, of patients admitted to hospitals in the U.S. and U.K., found that COVID-19 disease severity and fatalities were worse in patients with vitamin D deficiency.

Perhaps the populations hardest hit by COVID-19 are men and women living in nursing homes and assisted living facilities. This population is often at great risk of vitamin D deficiency as they are unlikely to spend much time in the sun, and even if they do, the ability to convert sunshine to vitamin D is diminished as we age.

Over 20 studies on the use of vitamin D in improving COVID-19 outcomes are in progress. We will need to assess the results of these studies, but at this point it seems wise to know your level and discuss with your health care practitioner ways to improve your level, if necessary.

D Does Not Work Alone

Nutrients in our body do not work alone. They have friends they rely on to function properly.

While most health care practitioners now routinely test for vitamin D levels, many overlook D’s reliance on magnesium. Magnesium helps to convert vitamin D to its final usable form, so without sufficient magnesium our body cannot properly utilize D. Up to half the people who take vitamin D supplements may not get much benefit, as without enough magnesium the vitamin D simply gets stored in its inactive form.

Some of my favorite magnesium-rich foods include spinach, swiss chard, kale, pumpkin seeds, almonds, cashews, quinoa, black beans, potatoes, figs and kelp seasoning.

How to Avoid a Deficiency

1. Test your D level

Before you adjust your vitamin D intake, it's important to have your level checked. Your doctor can order a simple blood test. Vitamin D researchers recommend a level between 40–60 ng/ml. Some health care practitioners recommend a slightly higher range of 50–70 ng/ml, but this is a discussion you should have with your personal physician.

2. Test your magnesium levels

While you are at it, ask your physician to test your magnesium as well. Magnesium is a common nutrient deficiency primarily due to soil erosion from over-farming. Half of the people taking vitamin D supplements are unable to normalize their vitamin D levels until they first boost their magnesium levels.

3. Sensible sun exposure

Spending time in the sun, without sunscreen (about 20 minutes, 3–4 times a week) will boost your D levels (assuming the sun is strong enough — check calendar here). Note that sunscreen interferes with vitamin D production.

4. Eat vitamin D-rich food

One of the best sources of vitamin D is salmon. A standard serving contains over 100% of the daily value for vitamin D (quality is critical with salmon — know the source). Sardines and mackerel are other good sources and the yolk of an (organic, cage-free) egg provides about 10% of daily value.

It's hard to get the amount of D you need for optimal function from food, which is why sunlight is so important, and why many health care providers recommend supplementation in the cooler months.

5. Discuss supplementation with your health provider

Since it’s difficult to get vitamin D exclusively through food, and most of us don’t spend enough time in the sun (or the sun is not high enough in the sky), supplementation may be advised. Some doctors may suggest you get your magnesium to an optimal level before beginning vitamin D supplementation.

GrassrootsHealth created this handy calculator based on the data from over 15,000 people supplementing with vitamin D. Input your weight, along with current and desired vitamin D levels, and it will suggest a dosage. It's always best to discuss dosage with your health care provider but this calculator is a great tool to bring to the conversation. Please note that this is merely an estimate and if your levels are low, it is a good idea to retest in three to six months.

Fat-soluble vitamins like D should be paired with healthy fats to be available in your body. If supplementing, make sure you have enough healthy fat in your diet.

With flu season upon us and a global pandemic that doesn't have a clear end in sight, it seems wise to stay on top of your vitamin D levels and discuss ways to keep your D levels optimized!

MJ O'Leary is founder and executive director of wellnessmultiplied. A certified Integrative Health and Wellness coach and mother of four, MJ has a BA in psychology from Gettysburg College, a certification in finance from the University of Chicago, and is a 2017 graduate of the Institute for Integrative Nutrition.
Find Your University
  • Sign up to receive awesome content in your inbox every week.

    We don’t spam! Read our privacy policy and terms for more info.

  • Connect

    Don't Miss Out!

    Get engaging stories and helpful information all year long. Join our college parent newsletter!