Vitamin D is a fat-soluble vitamin that plays a major role in keeping bones and teeth healthy. It is involved in modulating cell growth, neuromuscular and immune function, and inflammation reduction. Vitamin D can help fight infections, reduce risk of heart disease, and prevent diabetes, multiple sclerosis and certain types of cancers.
A recent study published in The Journal of Arthroscopic and Related Surgery found a correlation between vitamin D deficiency and risk for muscle strain and injury in young athletes, specifically college football players. The study included 214 college football players from the 2015 NFL Scouting Combine. The data analysis included the players' vitamin D levels, injury history and number of games missed because of a lower extremity muscle strain or core muscle injury.
The researchers found statistically significant differences in muscle injuries, with the rate increasing with the severity of the vitamin D deficiency. Of the 214 players examined, 126 (59 percent), were found to have an abnormally low vitamin D level, as measured in blood serum. These levels aligned with rates of injury. Players with normal vitamin D levels experienced leg muscle strain or core muscle injury only 40 percent of the time, while athletes with below normal vitamin D levels experienced these 56 percent of the time. For those with severe vitamin D deficiency, the proportion rose to 73 percent. Although the study doesn’t prove cause and effect, the correlation is strong. Additionally, of the 14 study participants who missed at least one football game due to this type of injury, 86 percent had significantly low levels of vitamin D. Lighter-skinned people can produce more vitamin D simply by exposing their skin to the sun. Interestingly, the study found that African-American athletes (70 percent) were more likely to have vitamin D deficiency than Caucasian athletes (13 percent).
Three-quarters of U.S. teens and adults are have vitamin D deficiency. This may be due to insufficient consumption of foods sources of vitamin D, limited sunlight exposure, having dark skin, abnormal intestinal absorption, kidney disease or obesity. A blood test is the most common way to detect a vitamin D deficiency and treatment is involves increasing vitamin D consumption through diet, supplements, and sunlight exposure if possible.
Vitamin D is naturally present in very few foods. It is found in salmon, tuna, mackerel and fish liver oils. Small amounts of vitamin D are found in beef liver, cheese, and egg yolks. Fortified foods provide most of the vitamin D in the American diet. The food we eat gives us a substance that is accumulated under our skin (7-dehydrocholesterol) and with the sun exposure, our skin turn this substance into vitamin D. It should be noted that the sun’s vitamin D synthesis is greatly influenced by season, time of day, latitude, altitude, air pollution, skin pigmentation, sunscreen use, passing through glass and plastic, and aging. Adults over 50 years may not produce vitamin D in their skin as well as they did when they were younger and may need to start taking a vitamin D supplement.
The Recommended Dietary Allowances (RDAs) represent a daily intake of Vitamin D that is sufficient to maintain health and normal calcium metabolism in healthy people. Below are the RDAs based on age and gender.
Recipe of the Week: Salmon with Brown Sugar and Mustard Glaze
3 tablespoons light brown sugar
1 tablespoon honey
2 tablespoons butter
1/4 cup Dijon mustard
2 tablespoons soy sauce
2 tablespoons olive oil
1 tablespoon finely grated ginger
Salt and freshly ground black pepper
8 salmon fillets, 6 ounces each
Preheat grill to medium heat.
On your grill’s side burner, melt brown sugar, honey and butter in a small sauté pan over medium-high heat. Remove from heat and whisk in the mustard, soy sauce, olive oil and ginger. Let cool.
Brush salmon with vegetable oil and season with salt and pepper to taste. Place the salmon skin-side down on the grill. Coat the flesh of the salmon with the brown sugar mixture. Grill for 6 to 8 minutes to medium doneness, turning once after 5 to 6 minutes.
Have a wonderful weekend,
Karen Alexander, BSND, MSCN