by Nate Widom
Here’s a little brain teaser: we get it when we’re outside, yet most of us don’t get enough. It helps us feel stronger and perform better; without it, our bones feel rough. What is it?
If you guessed vitamin D, you’d be right! Everyone needs it regardless of their diet or activity level, yet it’s one of the most common deficiencies today. I sat down with registered dietitian Jeannie Versagli to discuss why we all need vitamin D and, for our fellow gym-goers, why it’s especially critical for increasing and maintaining strength.
When it comes to building muscle, “everyone thinks it’s protein and creatine,” explains Jeannie. While these two nutrients certainly impact results, vitamin D is a critical missing piece to the equation. It’s directly linked to strength and prevention of aches and injuries. However, it’s beneficial for much more. Vitamin D can also improve the immune system, build strong bones, regulate insulin, reduce incidents of IBS, and support lung and cardiovascular health.
Symptoms of vitamin D deficiency may include:
- Depression
- Increased chances of sickness and infection
- Bone pain
- Fatigue
- Muscle pain
- Hair loss
- Impaired wound healing
Long-term vitamin D deficiency can lead to:
- Diabetes
- Obesity
- Hypertension
- Depression
- Fibromyalgia
- Chronic Fatigue Syndrome
- Osteoporosis
- The development of certain cancers
Unfortunately, many are deficient and may not even know it. Vitamin D deficiency is the most common medical condition globally; it even affects an estimated one billion people, according to a 2011 study.1 Another found a rate of deficiency of 41.6% in US adults.2
“If an individual is low in vitamin D, they’re going to be compromised with their strength,” Jeannie explains. No matter how much protein they consume, “they’re not going to be able to work at their optimum level.” A 2012 study even concluded that vitamin D increases “muscle protein synthesis, ATP concentration, strength, jump height, jump velocity, jump power, exercise capacity, and physical performance!”3
And when we talk about muscle-related injuries, things become even more eye-opening. “There’s research out there showing that people have an increase in muscle injury when they don’t have adequate vitamin D levels,” Jeannie describes. She sees this in real-time when watching football. Injuries are aplenty, with hurt players on the sidelines or when playing the game itself. Jeannie suspects that many of these minor injuries are related to deficiency.
Professional athletes are often touted as symbols of perfect health and performance. However, if you thought they wouldn’t be affected by vitamin D deficiency, think again. Studies show that deficiencies and their related injuries affect sports and are a growing concern in the industry.
More than half of respondents (60%) in a 2017 study of college football players were found to lack vitamin D. Ten percent were severely deficient. The researchers also discovered a much higher frequency of certain muscle strains and injuries in the vitamin D deficient players.4
Players with darker skin are more than 15 times more likely to have deficiencies, according to a 2014 study on NCAA D1 athletes. Furthermore, this study also linked low vitamin D levels to injury.5
It’s not just pro athletes who should care about their levels—it’s everyone. After all, we all use the muscles in our bodies every day. But Jeannie emphasizes the importance of healthy vitamin D levels for young athletes. Proper vitamin D levels will prevent their bones from being brittle and decrease the likelihood they’ll experience muscle injuries.
And it’s no wonder why a lot of us are deficient. Most of our vitamin D is obtained when UV rays from sunlight get absorbed into our skin. However, most of us are usually indoors, where window panes block the UV rays needed to synthesize vitamin D. When outdoors, clothing and sunscreen still limit the amount of vitamin D we can produce. Then there’s the sun itself. Its position, your location, and the time of year affect the amount of UV rays you’re exposed to. You’ll receive the most prime exposure in Delaware from March through November.
Vitamin D is also present in foods. Vitamin D2 is found in plant-based sources like soy and oat milk, while D3 is found in animal protein. The most common sources of vitamin D include oily fish like herring and cod, egg yolks, mushrooms, fortified milk, and fortified orange juice.
Vitamin D2 and D3 are slightly different in molecular structure, but D3 is absorbed better by our bodies. Simply put, both have the same benefits, but D3 is more effective. This is why D3 is always the best and most common choice for supplements.
While Jeannie notices increasing national concern over vitamin D levels, she knows firsthand it’s still a huge issue. “Most of the time, people come to me and have no clue what their vitamin D levels are,” she states. Of the many clients she’s seen over the years, only a few had a level within the acceptable range.
Currently, most insurance companies will not cover tests for vitamin D levels. However, vitamin D testing is on the rise. It is sometimes covered by insurance if you’re diagnosed with a deficiency by your doctor.
Races with darker skin complexions are more significantly impacted by vitamin D deficiency. The melanin in those with darker skin makes it harder for the sun’s rays to absorb into the body for vitamin D production. A study even found that about 82% of African Americans were deficient, along with about 69% of Hispanic Americans.2 Other at-risk groups include older adults and those who are overweight. Fat cells disrupt the ability of vitamin D to enter the bloodstream, so people with excess body fat will have a more difficult time receiving the nutrient. And, as we age, our bodies will be less able to convert vitamin D.
Jeannie urges the public to discuss their vitamin D level with their doctor and take a test. “That should be a standard. That should be like how cholesterol and blood sugar are drawn. It’s as important as that,” she concludes. If you suffer from symptoms of deficiency, consider taking supplements as well. However, it’s suggested to note the amount of IUs for the supplement, located on the label. Jeannie does not recommend consuming over 5,000 IUs per day unless a doctor has confirmed that your deficiency is severe.
References:
- ncbi.nlm.nih.gov/pmc/articles/PMC3126987/
- pubmed.ncbi.nlm.nih.gov/21310306/
- ncbi.nlm.nih.gov/pmc/articles/PMC3497950/
- hss.edu/newsroom_study-finds-college-football-players-have-inadequate-levels-of-vit-d.asp
- ncbi.nlm.nih.gov/pmc/articles/PMC4065560/
This article has been reviewed by Jeannie Versagli, RD, LDN. Jeannie is a Registered Dietitian with the Academy of Nutrition and Dietetics, a national professional organization, and is licensed in nutrition with the State of Delaware.
