A recent study investigated the effect of vitamin D on physical health, the immune system, and athletic performance, comparing the effect of dietary supplements with the importance of natural sun exposure.
Vitamin D is essential for good health, helping to regulate the immune system, maintain bone strength, and support muscle regeneration. Despite its importance, nearly one billion people worldwide suffer from a deficiency of this vitamin, particularly during winter when the body's production of UVB rays is reduced. The body produces about 80% of its vitamin D through sun exposure, while the remainder comes from food, making lifestyle and light exposure crucial factors in determining vitamin D levels.
In this context, researcher Eneko Fernandez from the University of the Basque Country (EHU), in collaboration with the University of Urbino in Italy, conducted a study involving runners and physically inactive individuals. Some participants took vitamin D supplements daily for eight weeks during the autumn and winter months, while others did not.
The results showed that it was normal for vitamin D levels to be elevated in those who took the supplements, but the surprise was that runners who did not take the supplements reached levels very close to those of non-runners who used them, because runners spend more time outdoors and are exposed to more sunlight during training.
According to the researcher, this indicates that exercising outdoors may be an effective and natural way to reduce vitamin D deficiency, in addition to other health benefits that are not provided by dietary supplements alone.
Regarding the immune system, the study indicated that vitamin D supplements may contribute to improving certain immune indicators, such as increasing the number of white blood cells, the body's primary line of defense against infection. However, this improvement does not prevent disease; it only helps support the balance of the immune system and enhance its response.
Regarding physical performance, the results showed no direct effect of vitamin D supplementation. Participants underwent tests measuring oxygen uptake, muscle strength, and jumping ability, and no differences were recorded between before and after supplementation.
The researcher confirms that vitamin D does not act as a stimulant and does not improve athletic performance, noting that the results were not surprising, but they confirmed that the runners generally have better fitness, even though they are amateurs and not professionals.
The researcher concludes that the best recommendation for maintaining good levels of vitamin D is to spend enough time outdoors during the winter, preferably while doing light physical activity such as running for 20 to 30 minutes, because this has benefits that go beyond simply raising vitamin levels.
