Supplementing your knowledge – Vitamin D

Supplements can play key roles in various aspects of your health. However, it can be hard to choose the right ones for you with so many out there. So we’re breaking down different supplements to help you get the most out of them with that in mind.

What do you and a plant have in common other than needing food and water? You both need sunshine.

While we often hear of the dangers of being overexposed to the sun, we do need it because the sun’s UV rays help our bodies make the nutrient vitamin D. Hence, its nickname the “sunshine vitamin.”

What You Need To Know About Vitamin D

When your skin is exposed directly to the sun, it converts a chemical into calciferol, an active form of vitamin D.

The amount of vitamin D your skin makes depends on many factors, including the time of day, season, latitude, and skin pigmentation. While essential to prevent skin cancer, sunscreen can also decrease vitamin D production. In addition, depending on where you live and your lifestyle, the winter months can cause your body to reduce or even stop vitamin D production.

Why is this important?

Vitamin D is a nutrient your body needs for building and maintaining healthy bones. Your body can only absorb calcium, the primary component of bone, when vitamin D is present. Vitamin D also regulates many other cellular functions in your body. It has anti-inflammatory, antioxidant, and neuroprotective properties that support immune health, muscle function, and brain cell activity.

One other key component in vitamin D deals with happiness, as research shows it might play an essential role in regulating mood and decreasing the risk of depression. That explains why you might’ve noticed how you feel better overall on sunny days, especially when you’re outside.

This is something you probably already know – more sunshine = more happiness. But what do you do when sitting in the sun is not an option every day?


From spring through fall, the only source of vitamin D most people need is sunlight. By the time your skin has turned light pink, it will have produced 10,000-25,000 international units (IU) of vitamin D. To put that in perspective, the recommended daily amount of vitamin D is 400 IU for children up to age 12 months, 600 IU for people ages 1 to 70 years, and 800 IU for people over 70 years.

And if that wasn’t enough, vitamin D is found in a small number of foods, such as fortified milk, fortified cereal, egg yolk, and fatty fish such as salmon, mackerel, and sardines. However, an analysis of data from the 2015–2016 National Health and Nutrition Examination Survey (NHANES) found that average daily vitamin D intakes from foods and beverages were just 204 IU in men, 168 IU in women, and 196 IU in children aged 2–19 years. So, chances are, you probably aren’t getting enough from your food.

Still, between going outside and food, it probably means buying vitamin D supplements shouldn’t be necessary, right? Yes, in a perfect world, but we don’t live in a perfect world.

The Nutrition Bulletin research says that locations between latitudes 40 degrees North and 40 degrees South generally get enough sunlight to help human skin produce vitamin D year-round. Still, you won’t get enough sun if you’re outside of that range. And even in that range, you still may not get enough. With skin cancer rates rising and a more sedentary lifestyle, people aren’t going outside near as much. And those that do still may not get enough, as a 2021 research from Scientific Reports shows air pollution can play a significant role in blocking the UV rays our own bodies use to make vitamin D. Older adults also can have trouble absorbing vitamin D, or even young ones with digestive and gastrointestinal disorders, such as Crohn’s disease, irritable bowel syndrome (IBS), or short bowel syndrome (SBS, or short gut), which can all block nutrient absorption in the gut.

It’s become such an issue that studies are being conducted to see if Vitamin D can be added to foods to help fight deficiencies.

While that’s ongoing, taking a multivitamin with vitamin D or a specific supplement may help. There are two forms of vitamin D available in supplement form: D2 and D3. Both are well absorbed in the intestinal tract of healthy people, but research is starting to show that D3 appears to be better at increasing blood levels. And as for the best way to take it, one study conducted at the Cleveland Clinic Foundation Bone Clinic found that people who took vitamin D with their biggest meal of the day absorbed the nutrient better, leading to an average 50 percent increase in levels over three months.