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Why Vitamin D Matters | Muscle & Body Magazine

mb.mayThe “sunshine” vitamin is also important for strength and fitness.

I have spoken in favor of proper supplementation time and time again, and today I’d like to further that notion with a lesson on vitamin D and its many benefits for athletes, including testosterone production and strength gains.

According to a study in the February 2012 issue of Medicine & Science in Sports & Exercise (official journal of the American College of Sports Medicine), “higher [vitamin D] concentrations are associated with improved cardiovascular outcomes, enhanced immune function and a reduced incidence of cancer.” In some studies, higher concentrations of vitamin D were also shown to increase muscle strength and performance, and were reported to increase serum testosterone levels in men.

In order to maintain and/or increase strength in these groups, you might consider checking your vitamin D levels via a blood test by a physician, because “vitamin D levels are directly associated with both arm and leg muscle strength.” Among other benefits of monitored and properly dosed vitamin D levels are a reported increase in serum testosterone levels for men.

It was found that “middle-aged men treated with 3,332 IU of vitamin D increased total testosterone, biologically active testosterone and free testosterone when compared with baseline over men treated with [a] placebo.” At this time, researchers haven’t fully determined how vitamin D increases androgen (a hormone that stimulates activity of the male sex organ); however, its cause could be due to the fact that vitamin D potentially decreases “the aromatization of testosterone to estrogen.” In other words, vitamin D may increase testosterone and possibly block the conversion of testosterone to estrogen—something a man of any age would welcome.

D3 Is Your Best Bet
While the dosage of vitamin D was specific to middle-aged men, let’s go ahead and discuss proper supplementation for our general audience. It’s important to take precautions when increasing vitamin D levels, because you can, in fact, have too much of it. Because it’s a fat-soluble vitamin—residing in adipose tissue—vitamin D’s excretion time from the body is longer than that of water-soluble vitamins like the B vitamins.

It was noted by the Natural Medicines Comprehensive Database that “taking vitamin D for long periods of time in doses higher than 4,000 units per day may cause excessively high levels of calcium in the blood.” As I previously mentioned, before beginning vitamin D supplementation, it’s best to have a physician determine your vitamin D levels via a blood test.

According to the National Institutes of Health, the recommended daily allowances (RDA) are as follows. Remember, vitamin D is measured in International Units, or IU. You will note the age range along with RDA:

  • Birth to 12 months: 400 IU

  • 1–13 years: 600 IU

  • 14–18 years: 600 IU

  • 19–70 years: 600 IU

  • 71 years and older: 800 IU

    I take at least 2,000 IU of vitamin D per day, however, I strongly urge you to consult your physician first before increasing your vitamin D supplementation. You might have a deficiency and require more vitamin D than what I have recommended, but again, a doctor can only establish this through blood work.

    The National Institutes of Health states, “In general, levels below 30 nmol/L (12 ng/mL) are too low for bone or overall health, and levels above 125 nmol/L (50 ng/mL) are probably too high. Levels of 50 nmol/L or above (20 ng/mL or above) are sufficient for most people.”

    They go on to say that rarely does an individual have a vitamin D level that is too high, but “young people [do] have higher levels of 25-hydroxyvitamin D than older people, and males have higher levels than females.”

    Maybe you are familiar with vitamin D but do not know which D to take—after all, there are five chemical compositions in the D family. Look for vitamin D as cholecalciferol D3. This is the form found in milk.

    It’s important to tell your doctor of any prescriptions you are taking, as vitamins can interfere with certain medications.

    Update On Sodium Bicarbonate

    In M&B’s November 2012 issue, I wrote that sodium bicarbonate was best paired with beta-alanine in regards to enhancing overall sports performance. However, new research indicates that sodium bicarbonate and creatine may be a stronger pairing.

    According to the Journal of Strength and Conditioning Research, “combining [sodium bicarbonate and creatine] may be advantageous for athletes participating in high-intensity, intermittent exercise.” During high-intensity exercise, athletes can become fatigued due to “muscle energy production, a decline in muscle ATP (a way of storing and using energy), or impaired electrochemical events of muscle contraction-relaxation production.”

    Sodium bicarbonate can increase hydrogen-ion buffering capacity, in turn delaying fatigue and increasing overall performance. And when creatine is paired with sodium bicarbonate, it has been hypothesized that, “combining these supplements would increase blood bicarbonate and pH and decrease lactate concentrations.” However, since there has been no creatine-only treatment, “it remains unclear whether combining the two supplements would have an additive effect on exercise performance.” It should be noted, though, that during a test on 100m swim performance, subjects were found to increase their performance levels and times when combining sodium bicarbonate and creatine.

    One of the top trainers in the world, Mackie Shilstone has worked with such sports superstars as Roy Jones Jr., Serena Williams and Bernard Hopkins. You can learn more about Mackie by visiting his website at

    Why Vitamin D Matters | Muscle & Body Magazine.