Vitamin D Talk

Vitamin D is touted as one of the essential micronutrients for good health.  It has implication in bone health, immunity and inflammation and even sports performance.  Many people however are not sufficient in this important Vitamin, which makes them more at risk for poor health outcomes.
 

Sources:

The main source of Vitamin D is definitely the good old sunshine.  Our skin contains a molecule called 7 dehydrocholesterol which is actually the precursor of the active form of Vitamin D, called D3.  When the UVA rays hit this molecule, they are absorbed and D3 is formed.  This is later metabolized in the liver and then the kidney to its eventual active form of Vitamin D that works to promote good health in the body.  Oral sources of Vitamin D are fatty fish like Salmon, egg yolks, cod liver, fortified milk and dairy products, and finally the classic supplement.  However, when purchasing a supplement utmost absorption can only be had through intake of Vitamin D3.  This the more natural kind that is found in our skin and in the food that we eat, whereas the D2 supplement is manufactured from plant/fungus sources in a lab, making it less compatible to our own bodies and harder to use, deeming it less effective for the health benefits that it has.  Vegetarians not to worry; rely on the sun, and take the D2 supplements (better than nothing) to ensure enough in your diet.  Also, look for enriched mushroom sources at your grocery store, or enrich them yourself!

Bone Health:

Have you recently had a bone scan done to check for density?  This Vitamin can play a large part in how well your results turn out.  Vitamin D along with Calcium is essential for greater bone density because of Vitamin D role in helping the calcium to become absorbed into the intestinal walls.  Vitamin D actually plays a large role in creating a protein that shuttles calcium through the intestinal wall and into the body tissues.  So without Vitamin D, there would be smaller amounts of the calcium transporter and less calcium brought through to the bones and muscles (1).  Additionally, its role as a secosteroid allows it to work with hormones called PTH and calcitonin in a cycle that function to maintain normal levels of calcium in the blood and normal bone calcium deposition. 

Inflammation:

This time of the year, it can be very easy to catch a cold or get sick.  But those who have more Vitamin D in the diet can help reduce their chances of catching a cold and setting themselves back in their daily life. There are many different sorts of inflammatory factors or cytokines in our blood that play a role in increasing how much our body is under stress, and we all know any kind of stress just doesn’t feel good. Vitamin D actually coordinates with special receptors on cells to release these pro and anti inflammatory cytokines.  One such bad cytokine is TNF- α which cause more of the white blood cells to be produced leading to increased infection and stress.  Many people who have lower counts of Vitamin D in their blood tend to get sick more often with common illnesses including upper respiratory tract infections because of this increase of inflammation and stress in their bodies.  For people who are getting proper amounts of Vitamin D, there is a great chance that it is helping to keep them healthy and more comfortable throughout the colder, sick months.

 Athletic Performance:

Finally, since I am a competitive athlete, I always like to find ways for improving performance.  That being said, there are many theories out there that question the importance Vitamin D provides for making the athlete, or exerciser bigger, faster, and stronger.  For one, increased Vitamin D can lead to improved VO2 max levels.  This is a measurement of how easy it is for your lungs and blood vessels to take in oxygen into the cells, and is a very important marker for performance.  The higher the level of your VO2 max , the easier it is to exercise and lose weight or get lean!  Second, since the active individual is more prone to infection because of the intense workouts that they put their body through, Vitamin D can help defend the body by decreasing the total systemic inflammation, kind of like an antioxidant!  The vitamin D level and upper respiratory tract infection have recently been studied extensively and there was found to be a positive correlation between increased Vitamin D status and increased anti-microbial peptides known as cathelicidines and an inverse relationship between the amount of Vitamin D and prevalence of URTI in the athletes.  The addition of adequate amounts of Vitamin D in the blood can help to reduce the time spent inflamed by enhancing anti inflammatory factors thus improving the healing process and preventing injury as a result of constant breakdown.  According to a recent review article, total mortality is 26% higher in those with lowest Vitamin D levels compared to the highest.  And third, the more Vitamin D and Calcium you get in your diet, the less chance of stress fracture occurrence you will have, and boy do I know how much those hurt.  If you are indoors, or take part in sports such as dancing or running, that emphasize leanness and are many times performed indoors, you are at greater risk and in greater need of Vitamin D.   

With all the important, scientifically backed health benefits for Vitamin D, it may be very helpful to give in and try to monitor your intake in order to get enough of it.  Also, it may be interesting to get a blood test to see if your levels are up to par with the recommendations.  I know I did after this cold snowy winter we have been having in New York!  And be sure to check out my friend's informational and entertaining bunch of "Fit Bits" as well.  She provides even more information to get you on your way to better health and wellness, including her own post about Vitamin D!