Add enhanced exercise performance to D's list of benefits
By Steve Born
Hammer pro tip: Recent research suggests that vitamin D may benefit not only cardiovascular health, but also exercise performance. Here's how to ensure that you receive adequate amounts of this essential nutrient...
Over the past several years, perhaps no nutrient has received more glowing press than vitamin D. That should come as no surprise, given the wealth of ongoing research that reveals its wide-ranging benefits for numerous health issues. In fact, pick pretty much any condition - hypertension, type 2 diabetes, heart disease, asthma, depression, rheumatoid arthritis, various types of cancer, and many more - and chances are that vitamin D plays a protective/ preventative role against such disorders.
But what about vitamin D's potential athletic performance benefits? Could vitamin D supplementation increase performance? According to a preliminary study performed by researchers at Queen Margaret University in Edinburgh, the evidence is very promising.
Previous research suggests that vitamin D can block the action of a specific enzyme needed to make cortisol, often referred to as the "stress hormone." It is believed that high levels of cortisol may be implicated in high blood pressure, as cortisol restricts arteries, narrows blood cells, and causes the kidneys to retain water. Because vitamin D is purported to reduce cortisol levels, it may help improve exercise performance as well as cardiovascular health.
In this particular study, researchers gave 13 healthy adults 2,000 IU of vitamin D daily or a placebo over a two-week period. Study participants who supplemented with vitamin D had lower blood pressure readings compared to participants who received the placebo. Vitamin D-supplemented participants also had lower levels of cortisol in their urine. Additionally, at the beginning of the study the group taking vitamin D was able to cycle 5 kilometers in 20 minutes; at the end of the study they were able to cover 6.5 kilometers in the same time. The researchers noted that in spite of cycling significantly farther in the same amount of time, the participants taking vitamin D showed lower signs of physical exertion compared to those who took the placebo.
Dr. Raquel Revuelta Iniesta, co-author of the study, stated "Our pilot study suggests that taking vitamin D supplements can improve fitness levels and lower cardiovascular risk factors such as blood pressure. Our next step is to perform a larger clinical trial for a longer period of time in both healthy individuals and large groups of athletes such as cyclists or long-distance runners." Vitamin D expert, Dr. Michael F. Holick, PhD, has stated that vitamin D is the most common nutrient deficiency in the world, and that three out of every four Americans are deficient in vitamin D.
Aside from fortified milk, cheese, yogurt, some fish, and mushrooms, there aren't a lot of food sources that contain appreciable amounts of vitamin D, which makes supplementation necessary, especially in the winter months in areas of the country where available sunlight is minimal.
The best way to know how much vitamin D you need is via a 25-hydroxyvitamin D blood test, also called a 25(OH) D test. Dr. Holick suggests that an ideal 25-hydroxyvitamin D blood level is 50 ng/mL.
Soak up the Vitamin D
Natural sources of vitamin D include sunlight as well as certain foods: yogurt, eggs, fish, cheese, fortified milk, and mushrooms. Many athletes, however, avoid dairy products. To be sure you are getting adequate levels of vitamin D for performance and health, supplement your diet with Premium Insurance Caps as well as a vitamin D specific supplement. Every 7-capsule dose of Premium Insurance Caps supplies 500IU of vitamin D3 (the preferred form), which provides a good start. Supplementing with additional amounts is easy as vitamin D3 supplements are readily available and relatively inexpensive.