Vitamin D: Are You Getting Enough?

The body stores vitamin D, a fat-soluble vitamin, in muscle, fat, and liver. Human skin contact with sunshine and nutrition are the main sources of vitamin D (Chen et al, 2007).

Vitamin D can be found in foods like oily fish, like salmon, and fortified foods like milk and margarine. Although the suggested level of some fortified foods may not always be correct, wild fish contains more than farmed fish (Chen et al, 2003).

By improving calcium absorption, vitamin D is crucial for the development and upkeep of strong bones. Rickets in children and osteomalacia and osteoporosis in adults can result from deficiencies (Holick, 2006).

During the summer, exposure to midday sunshine can produce enough vitamin D. However, dietary vitamin D supplementation is recommended due to varying climates and the danger of skin cancer from sun exposure (Chen et al, 2007). Longer sun exposure or a larger dosage of vitamin D supplements are also necessary for people with darker skin pigmentation (Owens et al, 2014).

Why Your Vitamin D Status Matters?

Because vitamin D interacts with the immune system, bone health, and muscular function, the vitamin D level is crucial for athletes. Despite living in sun-rich locations, athletes and the sporting community may have poor vitamin D status, especially in the winter (Owens et al. 2014).

1. Function of the Muscles

According to Owens et al. (2014), vitamin D insufficiency can affect muscular function and post-exercise muscle adaptations. Regarding vitamin D supplementation and the enhancement of muscular function in elite athletes, there are conflicting data. Because they are highly trained, athletes typically have smaller margins for improvement.

Nonetheless, sprint timings, jump height, and muscle adaptation and function have all improved in young athletes with vitamin D deficiency when they take large doses of supplements (Close et al, 2013). As a result, people who counsel or care for young athletes should pay close attention to vitamin D levels and how they affect sports performance.

2. Regeneration of Muscles 

Regarding vitamin D levels and muscle regeneration, there are conflicting data. The majority of the favorable results relate to elderly people and vitamin D insufficiency (Owens et al., 2018). For the best force recovery following muscle-damaging activity, Barker and colleagues (2013) found that a vitamin D concentration of more than 75 nmol/L is preferable. Monitoring your vitamin D status can be crucial for overall performance, even though it may not be clear whether vitamin D supplementation can improve muscle function in athletes at elite or non-elite levels. There is enough evidence to suggest that vitamin D deficiency results in worse muscle function.

3. Health of the Bones

Because vitamin D plays a part in calcium absorption, its relationship to bone mineral density is the most well-known function of vitamin D status. According to Owens et al. (2014), the primary goal of the IoM's vitamin D status classifications was to improve the general population's bone mineral density.

According to Holick (2004), dietary calcium absorption can vary from 10–15% in a deficient state to 15–30% in an adequate state. Vitamin D's primary role is to maintain blood calcium concentrations. During growth, pregnancy, or lactation, calcium absorption can reach as high as 60–80% of dietary calcium absorption. As a result, vitamin D levels are not only critical for bone health and overall athletic performance, but they are especially critical for female athletes and young athletes.

Participating in weight-bearing sports improves bone health, which may lessen the negative effects of low vitamin D on athletes' bone health. Nonetheless, it is still wise to make sure you have enough vitamin D, especially while engaging in non-weight-bearing activities like swimming and sports like gymnastics and combat sports that require weight-making or put you at risk of low energy availability (Ackerman et al, 2012).

There may be a connection between vitamin D status and the risk of bone injuries in athletic populations, even though environmental factors, including nutrition profile, training load, and genetic profile, play significant roles in the risk of stress fractures (McCabe et al, 2012). For this reason, vitamin D supplementation should also be taken into account.

4. Immune Response

The capacity of vitamin D to influence immunity is another important function. A lack of vitamin D can impair immune system performance and cause recurrent or more frequent infections (Owens et al., 2014).

Athletes are more susceptible to illness because of the intensity and frequency of their training, which can lead to overreaching and a slower rate of recovery, even if reasonable training programs can lower the frequency of illness (Gleeson et al, 2007).

He and colleagues (2013) demonstrated how the frequency of URTI symptoms is negatively impacted by reduced vitamin D levels in comparison to optimal vitamin D status. For athletes, maintaining adequate vitamin D levels should be a top priority, particularly in the winter when disease risk is increased.

Assessing Vitamin D Levels

The strongest predictor of vitamin D status is circulating 25[OH]D, which is often measured by extracting serum from blood samples. Different classifications of vitamin D status are described in the Institute of Medicine guidelines. Serum vitamin D values of 12.5 nmol/L (extremely deficient), 12-5-30 nmol/L (deficient), 30-50 nmol/L (insufficient), and >50 nmol/L are classified as acceptable or sufficient.

According to O'Malley & Mulkerrin (2006), vitamin D deficiency affects all age categories in Ireland, but it affects more than 75% of elderly women. According to Hill et al. (2004), all age groups showed an 11% deficit in the summer and 45% deficiency in the winter, indicating that at latitudes comparable to the UK, there is a greater requirement for vitamin D supplementation during the winter.

Because these categories are based on the Estimated Average Requirement (EAR) of vitamin D for bone health and do not account for other activities of vitamin D inside the human body, the IoM's guidelines are frequently contested (Manson et al., 2016).

A greater vitamin D status of 75–125 nmol/L is advised to maintain optimal health, according to Holick and colleagues (2004), who assert that vitamin D status at this level has no negative health impacts. Additionally, Owens and colleagues (2018) revealed that athletes benefit more from 25[OH]D concentrations larger than 75nmol/L, indicating that the IoM standards might not be appropriate.

Supplementing with Vitamin D

It is advisable to first comprehend the units related to vitamin D before using supplements. When talking about vitamin D supplementation, both micrograms (μg) and international units (IU) are frequently used. Understanding that 100iu = 2.5μg is crucial since misinterpreting the unit of measurement could result in poisoning.

Additionally, there are two types of vitamin D supplements: D2 and D3. According to Heaney and colleagues (2011), vitamin D3 is the preferred source of vitamin D supplementation since it is far more effective than vitamin D2. Vitamin D3 is used in Kinetica Sports' vitamin D3 oral spray for a more efficient supplementation regimen.

According to Owens et al. (2025), vitamin D supplementation should be customized because athletes' vitamin D status can vary depending on their sport, food, attire, and ethnicity (Chen et al, 2007). For instance, it has been demonstrated that indoor activities like dancing and basketball can cause vitamin D insufficiency.

For those with vitamin D levels below 75 nmol/L in the winter, when sun exposure is decreased, Owens et al. (2018) prescribe 2,000–4,000 IU of vitamin D per day. With a 3,000iu dose per serving, Kinetica Sports vitamin D3 oral spray provides the ideal answer to this suggestion.

How Much is Too Much?

Although vitamin D deficiency impairs many elements of athletic performance, the fat-soluble nature of vitamin D can lead to levels of toxicity when taking supplements. Zitterman (2003) and Owens et al. (2018), however, demonstrate that toxicity levels are far higher than the goal for adequate vitamin D sufficiency.

Conclusion

Bone health, immunity, and muscular function all depend on vitamin D levels, particularly for athletes who may be more vulnerable to disease and injury due to rigorous training.

The demand for vitamin D supplements varies greatly across individuals and can be influenced by a variety of factors, including sun exposure, clothing, training conditions, and dietary consumption. It is advised to have your vitamin D status checked by your physician due to the individuality of supplement requirements and the risk of toxicity from excessive supplementing.

Athletes may not always get the best results with blanket supplementation, but there is evidence to support taking higher doses of vitamin D than what is advised.

Anyone who is vitamin D deficient should take 2,000–4,000 IU of the vitamin, as deficits are found in a significant portion of the population. Each spray of Kinetica Sports Vitamin D3 contains 3000 IU of vitamin D3. This peppermint-flavored solution quickly and efficiently supplies your body with high-absorption vitamin D.