Vitamin D plays several crucial roles in the human body. One of the most important is regulating calcium and phosphorus metabolism, which is essential for bone health by increasing calcium absorption in the intestine and helping to maintain normal blood calcium and phosphorus levels. In addition, vitamin D is important for the functioning of the immune system, helping to protect the body against infections and autoimmune diseases.
Vitamin D deficiency is a growing concern in many countries, including Portugal. A study conducted on the Portuguese population indicated that a large proportion of the population has insufficient levels of vitamin D, especially during the winter and spring months when sun exposure is reduced. Other risk groups such as those with darker skin tone, being overweight, being from the Azores and advanced age are also prone to vitamin D deficiency (1).
Vitamin D deficiency is also very common among athletes. Increased use and depletion of stores may be important factors contributing to this higher prevalence in power sports athletes (65.4%) compared with endurance sports athletes (32.9%). Clinical characteristics of athletes at risk for vitamin D deficiency include female athletes with absent menses, athletes in jumping sports who have a history of stress fractures, athletes in indoor sports who need to maintain weight, and college student-athletes with busy schedules (2).
This deficiency can impair muscle function, resulting in muscle weakness and decreased athletic performance. Additionally, vitamin D plays a role in muscle recovery after exercise, and its deficiency can delay recovery and increase the risk of injury (2).
To prevent vitamin D deficiency, moderate sun exposure of 10 to 30 minutes per day, several times a week, depending on skin type and geographic location, is recommended. However, sun exposure should be balanced to avoid
risks associated with UV radiation, such as skin cancer. In addition to sun exposure, it is important to include food sources of vitamin D in the diet. Foods such as fatty fish (salmon, sardines), eggs, and fortified foods (such as some dairy products and cereals) are good options. In some cases, especially for individuals at risk of deficiency, vitamin D supplementation may be necessary, but should be done under medical supervision to avoid toxicity (3).
Marinho Ribeiro
(1) Prevalence of vitamin D deficiency and its predictors in the Portuguese population: a nationwide population-based study
(2) Vitamin D deficiency in athletes: Laboratory, clinical and field integration
(3) National Health Service. (2023). Vitamin D.