In a recently published issue of Arthroscopy, the Arthroscopy Association of North America’s official journal, the editorial commentary discussed how Vitamin D is important for preventing muscle fatigue in athletes.
The current estimate is that more than a billion people are Vitamin D deficient. In studies involving athletes, one study found that of 214 athletes in 2015 NFL combine, 10% were Vitamin D deficient while 59% had insufficient levels of Vitamin D. In another study conducted at an orthopedic surgery center, it was found that 43% of those scheduled to have orthopedic surgery lacked Vitamin D, with 40% of these patients being Vitamin D deficient.
Also known as the sunlight vitamin because it is naturally produced in our body when sunlight strikes our skin, Vitamin D is important for our bone metabolism and to maintain potassium and calcium homeostasis in our body. When we suffer from Vitamin D deficiency, it can lead to thin and brittle bones. In athletes, having deficient levels of Vitamin D increases the risks of incurring detrimental injuries.
Vitamin D Deficiency Symptoms
The symptoms of Vitamin D deficiency are not easily observed. Usually, when the condition has gotten so much worse and has been occurring for a long time, that’s when the symptoms already become severe.
- Hair Loss – Rickets, which has long been associated with Vitamin D deficiency, is also associated with alopecia areata. This, in turn, causes severe hair loss. Normally, one would associate hair loss with stress and other factors such as genetics. However, when the hair loss is already severe, the culprit could be Vitamin D deficiency.
- Low bone mineral density – Since Vitamin D is crucial in bone metabolism as well as in calcium absorption, when there is insufficient Vitamin D in the body, it also leads to impaired calcium absorption. In athletes, this is particularly problematic because when their bones become brittle due to bone loss, this places them at a higher risk for more severe injuries such as fractures.
- Depression – Young athletes may have a lower risk for Vitamin D deficiency-related depression, but this could be problematic for older athletes. Many studies have shown the association between low Vitamin D levels and depression. If we add to the picture the stress of participating in highly competitive sports, and the risk for athletic performance anxiety, athletes with low levels of Vitamin D become more prone to depression.
- Back Pain – Several studies have shown the link between back pain and insufficient levels of Vitamin D. In some cases, the pain could be severe, enough to prevent someone one from engaging in daily activities. Again, this particular symptom is particularly problematic for athletes because they usually just attribute back pain and muscle pains to their strenuous physical activities. Hence, the symptom often gets disregarded.
- Muscle Weakness – A 2013 study said that proximal muscle weakness is present in 30% of patients who have low Vitamin D levels. Moreover, muscle weakness as a symptom was found to present itself before the other biochemical symptoms of Vitamin D deficiency appeared. As with back pain, athletes may simply overlook this symptom or attribute it to their intense physical activities. However, when addressed immediately, the condition is easily reversible. All it would take is to increase Vitamin D consumption, either through proper diet or supplementation.
Foods That Contain Vitamin D
There are actually not a lot of foods that contain Vitamin D naturally. The recommended dietary allowance (RDA) for Vitamin D is 400 IU – 800 IU, depending on the age. For older people who are more at risk of bone loss and osteoporosis, 800 IU is recommended. The recommended Daily Value (DV) for adults is only 400 IU. Here are examples of foods that are high in Vitamin D %DV.
- Swordfish (3 ounces, cooked) – 142 % DV
- Salmon (3 ounces, cooked) – 112% DV
- Tuna fish (3 ounces, canned, drained) – 39% DV
- Cow liver (3 ounces, cooked) – 11% DV
- Egg (large, yolk) – 10% DV
You can also buy Vitamin-D fortified products, just make sure to check the label for their Vitamin D content. Such products are readily available in supermarkets like milk, cereals, orange juice, and even yogurt.
Aside from eating more of these foods, you can also increase your exposure to sunlight, as that is one way to synthesize Vitamin D in the body naturally. Of course, this is not to say that you should stay outside for hours. But an additional five minutes here and there can also help.
Benefits Of Increasing Vitamin D Intake
Increased Muscle Strength – Previous studies tell us that there is a strong link between low levels of Vitamin D and lack of muscle mass. A United Kingdom study published recently indicated that having high levels of active Vitamin D can help improve muscle strength.
Although the mechanism of how Vitamin D affects muscle strength is not yet fully understood, it is clear that those who want to develop their muscle strength, especially athletes, need to make sure that they have sufficient levels of Vitamin D, if only to prevent muscle weakness.
Reduced Injury Rates – According to the editorial commentary mentioned earlier, the chances of incurring core muscle injuries, lower extremity muscle strains, and hamstring injuries double in athletes who suffer from Vitamin D deficiency. The commentary further stressed that for the general population, such injuries may not be significant, but for elite athletes, not being able to address this easily reversible condition may lead to career-impacting injuries. To avoid this from happening, athletes can readily lower their risks of injury by simply increasing their Vitamin D intakes.
Another study involving an NFL team found that players who were uninjured had higher levels of Vitamin D, whereas players who were injured had much lower levels of Vitamin D. Among the athletes included in the study, a full 30% were Vitamin D deficient.
Improved Sports Performance – One study listed the potential benefits of Vitamin D sufficiency in relation to sports performance. The results showed that increasing levels of Vitamin D can help improve athletic performance – To cite a few examples, physical performance, exercise, capacity, jump height, and muscle protein synthesis were found to improve after increasing Vitamin D intake.