How does Vitamin D work?
Put simply, once Vitamin D has been ingested through food or produced in the skin, the liver and kidneys convert it to its active form, called 1,25-dihydroxyvitamin D, or Vitamin D3. Long thought to be the "bone vitamin", new data shows that every cell in our bodies has receptors for vitamin D. According to recent studies by Michael Holick, MD, a pioneer in Vitamin D research, much higher doses of this nutrient are needed for optimal functioning than previously recommended. What this means is that most Americans are deficient, presenting a host of problems like early onset diabetes, dementia, heart disease and of course bone loss.
As an athlete, why do I need Vitamin D?
More and more research is coming out about the importance of Vitamin D, especially in athletes. See the list below.
- Increases your VO2 Max: A higher VO2 max is a very good thing for swimmers. Being that swimming is already a hyporic sport, having a higher VO2 Max means that your body is more efficient in getting and delivering oxygen to your muscles thus enabling you to train harder.
- Reduces Inflammation: After intense exercise, your body usually experiences higher levels of inflammation due to higher levels of cytokines (proteins that are important for cell signaling). Having enough Vitamin D reduces the production of cytokines while increasing the levels of anti-inflammatory cytokines, which in turn speeds your recovery process.
- Improved Immune System: A study was released in 2009 by the Archives of Internal Medicine, showing that of 19 000 people, those with the lowest levels of Vitamin D had the highest chances of getting colds. This becomes even more important for athletes since you are already putting your body through a ton of stress, which in turn increases your chances of getting sick.
- Bone Health: Vitamin D plays a very important role in protecting and strengthening your bones. Your body also requires it to absorb calcium.
How do I know if I'm deficient?
During summer months, if you're eating a balanced diet and are in the sun, chances are you are getting enough Vitamin D. But as we move into the colder months with shorter days, we are spending less time outdoors and risk becoming deficient. Also, studies show that young swimmers are usually deficient in Vitamin D, Calcium, and Iron. Since it is imperative that you get the right nutrients to support healthy development and speedy recovery, make sure that you are getting adequate amounts of Vitamin D. If you are training indoors, it is highly likely that you are deficient and not getting enough sunlight to synthesize this vitamin. Check with a health professional to find out your exact levels, but in the meantime, supplement your sun exposure with food.
What are good sources of Vitamin D?
Vitamin D is found in food sources such as fish, especially salmon and tuna, eggs, and can also be found in fortified cereals and milk. If you're taking a vitamin, Vitamin D3 supplementation (cholecalciferol) is recommended over D2 supplementation (ergocalciferol), since D3 is used more effectively in the body. Make sure to get somewhere between 1,000 IU to 4,000 IU per day, depending on your body size and type. During the winter months, look at getting more Vitmain D3 than during summer when you are more likely to be training outdoors.
Ultimately, check with your health professional or nutritition coach to find out how much Vitamin D you need, based on your training goals and your body type. Whatever your needs are, you'll find that integrating this cornerstone nutrient into your diet will give you improved health and a competitive edge!