|
Could it be true that taking vitamin D regularly can improve
your personal athletic performance? Could you throw the ball a little faster?
Hit a baseball longer distances? Or run the bases a little faster?
According to a leading expert, vitamin D is a natural and safe
steroid hormone that a player could use to boost his performance on the field
with no negative side effects. If the player’s vitamin D level is low, then by
taking supplements, he can increase his speed, muscle mass, and strength and
improve his balance and reaction time just be boosting his body’s vitamin D to
an optimal level without otherwise changing his personal conditioning routine.
The Germans and Russians won many Olympic medals in the 1960s and 1970s, and
their trainers and scientists believed vitamin D was their natural wonder drug.
They supplemented their elite athletes with vitamin D, and study after study
showed that by raising the body’s level of vitamin Dy, any athlete, whether a
weekend warrior or an Olympic Medal winner, achieved top competitive performance
when his vitamin D level was increased so that it was on a par with the vitamin
D level found in the body of a lifeguard in the middle of the summer season.
Before the days of sunscreens and avoidance of time in the sun, we received the
vitamin D we needed–at least during the summer. In the modern world, we have
neither the time nor the inclination to grab rays from the sun each day. The
only practical way to get the vitamin D we need is by taking supplements.
If you are one of the rare individuals whose body has sufficient vitamin D, then
you will not be able to gain from taking supplements. However, if you are like
most people, your blood serum levels of vitamin D will be below the optimal
level, and you can gain an athletic advantage by taking supplements to boost
your vitamin D levels.
How can you know if you are vitamin D deficient? The sun is the main source of
vitamin D, and most people avoid being in the sun regularly without protective
covering. Did you know that in addition to blocking ultraviolet rays, suncreens
also block the vitamin D that the sun freely provides? So unless you regularly
spend a few hours a day exposing large areas of your skin to the sun without
cover of a sunscreen, the chances are great you are vitamin D deficient. Even if
you spend a fair amount of time in the sun, if you live anywhere north of
Atlanta, Georgia, then in the winter you will need to take vitamin D supplements
because the tilt of the earth during the winter is such that the atmosphere acts
as a filter that keeps the vitamin D from you.
If you are not sure and want to know the vitamin D you have in your body, you
can ask you doctor to arrange a blood test. If your 25-hydroxyvitamin D
[25(OH)D] count is in the range of 30 to 50 ng/mL, you are not deficient, and
the closer you are to 50, the more likely your athletic performance will be at
its peak in terms of the influence of vitamin D.
So if you are vitamin D deficient, can you stick to your normal athletic routine
and make gains just from taking vitamin D orally and raising your blood serum
levels? The answer is yes. This is one of the easiest ways ever conceived to
gain athletically without breaking any additional sweat. According to Dr. John
Cannell, the author of the scientific article presented below, you need to take
1,000 IU (international units) of vitamin D for every 30 pounds of weight. So if
you weigh 180 pounds, you would need to take 6,000 IU per day. You can find
vitamin D in any vitamin store and in most supermarkets. It is common and
inexpensive. The most practical format is to purchase it in 1,000 IU and/or
2,000 IU formats. For example, if you weigh 210 lbs., you would want to average
7,000 IU per day. You could achieve this by taking three 2,000 IU capsules plus
one 1,000 IU capsule each day. Or, if you wanted to purchase on 2,000 IU
capsules, then you could take three capsules one day and four capsules the next.
One other point of technical clarification: You want to purchase vitamin D-3,
which is the more active version, rather than the D-2 version. In most vitamin
stores, you will only find the D-3 version.
Dr. Cannell did a great deal of research, and discusses the various scientific
studies that he reviewed. The full story, which is excerpted with permission
from the March 2007 Issue of the Vitamin D Newsletter, is presented below. - Ed.
---------------------------------------------------------------------------------------------------
Peak Athletic Performance and Vitamin D
by John Jacob Cannell MD
Executive Director,Vitamin D Council
www.vitaminDcouncil.org
Vitamin D - a Steroid Hormone
The active form of vitamin D is a steroid (technically a
secosteroid) in the same way that testosterone is a steroid. It is also a
hormone (from the Greek, meaning "to set in motion") in the same way that growth
hormone is a hormone. Steroid hormones are substances made from cholesterol that
circulate in the body and work at distant sites by setting in motion genetic
protein transcription. That is, both vitamin D and testosterone set in motion
your genome, the stuff of life.
While testosterone is a sex steroid hormone, vitamin D is a pleomorphic steroid
hormone. ( Pleomorphic means it can assume different forms.) Certainly steroids
can improve athletic performance—although they can be quite dangerous. In
addition, few people are deficient in growth hormone or testosterone, so
athletes who take sex steroids or growth hormone are cheating, or doping. The
case with vitamin D is quite different because natural vitamin D levels are
about 50 ng/mL and since almost no one has such levels, extra vitamin D is not
doping, it's just good treatment.
I spent more than a year exhaustively researching the medical literature on
vitamin D and athletic performance. I discovered that five totally independent
bodies of research that all converge on an inescapable conclusion: vitamin D
will improve athletic performance in vitamin D deficient people (and that
includes most people in our modern era of sun avoidance and widespread use of
sun screens.)
Even more interesting is who published the most direct literature, and when. Are
you old enough to remember when the Germans and Russians won every Olympics in
the '60s and '70s? Well, it turns out that the most convincing evidence that
vitamin D improves athletic performance was published in old German and Russian
medical literature.
I was able to review translations of the old Russian and German literature.
Combining that old literature with the abundant, modern, English-language
literature on vitamin D and neuromuscular performance, the conclusion was
inescapable. If you are vitamin D deficient, the medical literature indicates
that the right amount of vitamin D will make you faster, stronger, improve your
balance and timing, etc.
How much it will improve your athletic ability depends on how deficient you are
to begin with. How good an athlete you will be depends on your innate ability,
training, and dedication. However, peak athletic performance also depends upon
the neuromuscular cells in your body and brain having unfettered access to the
steroid hormone, activated vitamin D. How much activated vitamin D is available
to your brain, muscle, and nerves depends on the amount of 25-hydroxyvitamin D
in your blood. In turn, how much 25-hydroxyvitamin D is in your blood depends on
how much vitamin D you put in your mouth or how often you expose your skin to
UVB light.
One might ask why I would write about such a frivolous topic like peak athletic
performance when cancer patients all across this land are dying vitamin D
deficient. The reason is that, like many vitamin D advocates, I have been
disappointed with the medical profession's and the public's lack of enthusiasm
over vitamin D. Maybe people like the young basketball player I found was
vitamin D deficient will take an interest in vitamin D if they know of its
potential benefit to their athletic performance?
Let's see... Hey jocks! Want to improve your game? Take vitamin D. Listen up—I'm
talking speed, balance, choice reaction time, muscle mass, muscle strength,
squats, reps—important stuff! Want to learn more? Here's the first-ever Sports
Edition Vitamin D Quiz:
1. East German and Russian Olympic athletes have used UVB radiation to
strengthen their performance. True or False?
True! I found tantalizing evidence that the Russians, and
especially the East Germans, possessed the knowledge that vitamin D increases
physical performance, and used it to their advantage during the '60s and '70s
when those two nations took turns placing first and second in the Olympics.
In 1938, Russian researchers reported that a course of ultraviolet irradiation
improved speed in the 100-meter dash in college students compared to matched
controls, both groups undergoing daily training. Average 100-meter dash times
decreased from 13.51 seconds to 13.28 seconds in the non-irradiated training
students, but from 13.63 seconds to 12.62 seconds in the irradiated students
undergoing training. Here we see training improved times but training and
irradiation improved times much more. Obviously, irradiation or vitamin D would
not render the same magnitude of improvements in world-class sprinters, but they
might be happy with a few milliseconds. (Source: Gorkin Z, Gorkin MJ, Teslenko
NE - The effect of ultraviolet irradiation upon training for 100 meter sprint.
The Journal of Physiology of the USSR [Fiziol, z. (RSSR)] 1938;25: 695–701. In
Russian.)
If you would like to know what German scientific-thinking was, read this
summation of the early German literature:
"It is a well-known fact that physical performance can be
increased through ultraviolet irradiation. In 1927, a heated argument arose
after the decision by the German Swimmers' Association to use the sunlamp as an
artificial aid, constituting an athletic unfairness, doping, so to speak. In
1926, Rancken had already reported the improving effect of sunlamp irradiation
on muscle work with the hand-dynamo graph. Heib observed an improvement in
swimming times after repeated irradiations. In thorough experiments, Backmund
showed that a substantial increase in muscle activity happens after radiation of
larger portions of the body with an artificial sunlamp; that this performance
increase is not caused through local (meaning direct or indirect) effects on the
musculature, but through a general effect. This general effect, triggered by
ultraviolet irradiation, is caused by a systemic effect on the nervous system."
(Source: Parade GW, Otto H Die beeinflussung der leistungsfahigkeit durch
Hohensonnenbestrahlung.Zeitschrift fur Klinische Medizin (Z Klin
Med),1940;137:17–21. In German.)
In 1945, two Americans measured the cardiovascular fitness and muscular
endurance of 11 male Illinois subjects undergoing training in an indoor physical
education class, comparing them to ten matched controls. Both groups underwent
similar physical training. Treatment consisted of ultraviolet irradiation, given
in the nude, up to two minutes per session, three times per week, for ten weeks
in the late fall and winter. After ten weeks, the treatment group had a 19%
standard score gain in cardiovascular fitness compare to a 2% improvement in the
control students. To regular readers of this newsletter, it should come as no
surprise that the un-irradiated control group reported twice as many viral
respiratory infections as the treatment group. (Source: Allen R, Cureton T
Effects of Ultraviolet Radiation on Physical Fitness.Arch Phys Med
1945;10:641–44.)
In 1952, the German sports medicine researcher, Spellerberg, reported on the
effects of wholesale irradiation of athletes studying and training at the Sports
College of Cologne—including many elite athletes—with a "central sun lamp." The
College routinely irradiated athletes in their bathing suits, on both sides of
their bodies, for up to ten minutes, twice a week, for six weeks, resulting in a
"convincing effect" on athletic performance and a "50% reduction" in chronic
sports injuries.
Results were particularly impressive for swimmers, soccer, handball, hockey, and
tennis players, as well as for boxers and most track and field athletes. He
reported that irradiation leading to burns, further irradiation of athletes
having achieved peak performance, and irradiation within 24 hours of
competition, all impaired athletic performance. Their results were so
convincing, the “Sports College of Cologne officially notified the National
German and International Olympic committee." (Source: Spellerberg AE Increase of
athletic effectiveness by systematic ultraviolet irradiation.Strahlentherapie.
1952;88(3–4):567–70. In German.)
In 1952, Ronge exposed 120 German schoolchildren to UV lights installed in
classrooms and compared them to 120 un-irradiated control children. Over a
two-year period—excluding summer vacations—he tested both groups with a series
of six cardiovascular fitness tests using a bike ergometer. Un-irradiated
children showed a distinct seasonality in fitness, with the highest values right
after summer break and the lowest values in the spring. Treated children showed
no seasonal differences in physical performance. Differences in work performance
between the irradiated and un-irradiated children were most conspicuous in the
spring with 56% difference between the two groups. In a final experiment, he
gave 30 children in the control classrooms 6.25 mg (250,000 IU) of vitamin D as
a single dose in February and found their performance had "increased
considerably," one month later but did not report the actual numbers. He
concluded that vitamin D, either as a supplement or induced via UV irradiation,
improved physical performance. (Source: Ronge HE Increase of physical
effectiveness by systematic ultraviolet irradiation. Strahlentherapie 1952;
88:563–6. In German.)
In 1954, another researcher, at the Max-Planck Institute for Industrial
Physiology in Dortmund, Germany, conducted an eight-week study during which he
administered three different wavelengths of UV light to university students. He
found that ultraviolet light in the vitamin D-producing UVB range was
consistently effective in reducing resting pulse, lowering the basal metabolic
rate, and increasing athletic performance. UVA had no effect. Interestingly,
artificial UVC irradiation (normally completely filtered out by the atmosphere
and therefore not naturally present on earth) also gave some positive results.
(Source: Lehmann G Significance of certain wave lengths for increased efficacy
of ultraviolet irradiation. Strahlentherapie. 1954 Nov;95(3):447–53. In German.)
In 1956, Hettinger and Seidel irradiated seven subjects in two different
experiments: athletic performance on bike ergometers and forearm muscle
strength. They found that UV radiation induced a significant improvement in both
muscle strength and athletic performance. (Hettinger T, Seidl E Ultraviolet
irradiation and trainability of musculature. Int Z Angew Physiol. 1956;
16(3):177–83. In German.)
Another German researcher, at the Institute for Medical Physics and Biophysics
at the University of Gottiingen, studied reaction times (the time needed to
recognize a light and switch it off) during October and November in a series of
controlled experiments on 16 children and an unspecified number of adults. He
first controlled for practice effects (getting better by practicing) and then
administered nine full-body, UV radiation treatments over three weeks to the two
treatment groups, using placebo radiation in the two control groups. UV
radiation improved choice reaction time by 25% in the children and 20% in the
adults while reaction time worsened in the controls. The improvements in the
irradiated groups peaked at the end of the three weeks of UV treatments,
reverting to baseline levels three weeks later. In the two control groups, he
found distinctly improved reaction times in the sunnier months. (Sigmund R
Effect of ultraviolet rays on reaction time in man. Strahlentherapie. 1956;
101(4):623–9. In German.)
The next study threw me because it was very well conducted, meticulously
designed, and completely negative. In 1963, Berven reported on the effects of
ultraviolet irradiation and vitamin D supplementation in a group of 30 Stockholm
schoolchildren, aged 10–11, comparing them to appropriate controls. He found no
seasonality of fitness in the control group and no effect on bike ergometer
performance from either irradiation or from two different protocols of vitamin D
supplementation: 1500 IU of cholecalciferol daily for two months or a single
dose of 400,000 IU of ergocalciferol. (Source: Berven H The physical working
capacity of healthy children. Seasonal variations and effect of ultraviolet
irradiation and vitamin D supply. Acta Paediatr Suppl. 1963; suppl 148:1–22.)
However, two things were not right and got me thinking. One, Berven found no
seasonality of physical fitness and was the only author who found no such
seasonal variations in athletic performance. Second, he found no effect from
irradiation—again, the only author to do so. Then I realized he was working with
Swedish children in the late 1950s. Supplementation of children with high doses
of vitamin D, often as cod liver oil, was routine in Scandinavia in the past,
particularly in children. For example, in neighboring Finland, the official
recommended daily dose of vitamin D for children, including infants, was 4,000
IU/day until 1964, when authorities reduced it to 2,000 IU/day—yes, you read
that correctly—4,000 IU per day for infants, a level which is too much for
infants. (Source: Hypponen E, et al. Intake of vitamin D and risk of type 1
diabetes: a birth-cohort study. Lancet. 2001 Nov 3;358(9292):1500–3.)
Hypponen reports that, in 1975, Finnish authorities reduced the recommended dose
to 1,000 IU/day. In 1992 they reduced it even further, to 400 IU/day. I emailed
Professor Elina Hypponen who confirmed that the Swedish recommendations were
similar to the Finnish ones. Therefore, it seems highly unlikely that many of
Berven's Swedish children, studied in 1958 and 1959 and all from "families with
a good standard of living," were vitamin D deficient. Therefore, this study
showed that vitamin D will not improve athletic ability in vitamin D replete
people. That's very important because it indicates that more is not necessarily
better, it's only better if you are not taking enough.
In the 1960s, three American researchers conducted experiments with university
students. Rosentswieg studied the effects of a single six-minute dose of UV
light on each side of the trunk in 23 college women. In various tests he
recorded changes of muscle strength at one and five hours. He found a trend
towards significance after five hours in the white students, but not in those
who were black. Then, in 1968, Cheatum found that a six-minute administration of
UV light on each side of the trunk increased the speed of 15 college women in
the 30-yard dash and in1969, Rosentswieg found it improved bicycle-ergometer
performance in college women. However, unlike the Germans and Russians, I could
find no evidence that any of these American findings interested any American
professionals involved in the care or training of athletes. (Source: Rosentsweig
J The effect of a single suberythemic biodose of ultraviolet radiation upon the
strength of college women. J Assoc Phys Ment Rehabil. 1967 Jul–Aug; 21(4):131–3.
Cheatum BA Effects of a single biodose of ultraviolet radiation upon the speed
of college women. Res Q. 1968 Oct;39(3):482–5. Rosentswieg J The effect of a
single suberythemic biodose of ultraviolet radiation upon the endurance of
college women. J Sports Med Phys Fitness. 1969 Jun;9(2):104–6.)
2. True or False? Athletic performance peaks in the winter and is lowest in
the summer.
False. The studies below show that tests of physical
performance peak in the summer (when vitamin D levels peak), start to decline in
early autumn as vitamin D levels decline, and reach their lowest point in late
winter (when vitamin D levels bottom out.) However, it is reasonable to assume
that any associations between athletic performance and summer season may be due
to "reverse causation." That is, improved athletic performance in the summer
might be secondary to increased outdoor physical and recreational activity in
the warmer weather with an indoor sedentary lifestyle during the colder months.
Maybe people have better athletic ability in the summer simply because they
exercise more? If that is true—and using the same logic—athletic performance
should not begin to decline until late autumn, because at most temperate
latitudes early fall weather is ideal for outdoor physical activities.
However, some of the studies below did control for seasonal variations in time
spent exercising. Besides a consistent positive association of summer season
with improved athletic performance, they found an unexplained, abrupt reduction
in athletic performance beginning in the early fall, when vitamin D levels
decline.
For example, in 1956, German researchers found a distinct
seasonal variation in the trainability of musculature when studying wrist flexor
strength in 21 German subjects undergoing daily training. They found highly
significant seasonal differences with peak performance in late summer and an
unexplained sharp decline beginning in October followed by nadirs (low points)
in the winter. (Source: Hettinger T, Muller E ASeasonal course of trainability
of musculature. Int Z Angew Physiol. 1956;16(2):90–4.)
A study of Polish pilots and crew found physical fitness and tolerance to
hypoxia were highest in the late summer with an unexplained sharp decline
starting in September. The authors hypothesized that seasonal variations in an
unidentified hormone best explained their results. (Source: Kwarecki K, Golec L,
Klossowski M, Zuzewicz K Circannual rhythms of physical fitness and tolerance of
hypoxic hypoxia.Acta Physiol Pol. 1981 Nov–Dec;32(6):629–36.)
Cumulative work ability among 1,835 mainly sedentary Norwegian men during
bicycle exercise tests also showed an August peak, a sharp decline in autumn,
and a wintertime nadir. There were no seasonal changes in body weights, as would
be expected if it was more caloric-demanding recreational activity during the
sunnier months that explained their results. (Source: Erikssen J, Rodahl K
Seasonal variation in work performance and heart rate response to exercise. A
study of 1,835 middle-aged men. Eur J Appl Physiol Occup Physiol. 1979 Oct;
42(2):133–40.)
Koch and Raschka controlled for seasonal variations in the time spent exercising
by instituting a controlled year-long training regimen beginning in December.
The training regimen consisted of at least 20 push-ups/day and two or three long
distance races each week for the entire year. They found that both the number of
push-ups and muscle strength peaked in late summer followed by a rapid decline
in the fall, and a nadir in the winter despite continued training. They
concluded that seasonal variations in an unidentified hormone best explained
their results. (Source: Koch H, Raschka C Circannual period of physical
performance analysed by means of standard cosinor analysis: a case report.Rom J
Physiol. 2000 Jan–Dec; 37(1–4):51–8.)
3. True or False? Vitamin D stimulates growth of muscle fibers that are
critical to athletic ability.
True. Both animal and human studies have found that vitamin D increases
muscle mass in subjects who are vitamin D deficient. Birge and Haddad found that
vitamin D caused new protein synthesis in rat muscle. (Source: Birge SJ, Haddad
JG 25-hydroxycholecalciferol stimulation of muscle metabolism. J Clin Invest.
1975 Nov; 56(5):1100–7.)
As for humans, in 1981 Young performed muscle biopsies on 12 severely vitamin D
deficient patients, both before and after vitamin D treatment. He found that
type-2 (fast-twitch) muscle fibers, small before treatment, became significantly
enlarged after. Sorensen performed the same study on 11 older patients with
osteoporosis and had the same results—an increase in muscle fibers despite lack
of physical training. (Source: Young A, Edwards R, Jones D, Brenton D Quadriceps
muscle strength and fibre size during treatment of osteomalacia. In: Stokes IAF
(ed) Mechanical factors and the skeleton. 1981. pp 137–145. Sorensen OH, Lund B,
Saltin B, Lund B, Andersen RB, Hjorth L, Melsen F, Mosekilde L Myopathy in bone
loss of ageing: improvement by treatment with 1 a-hydroxycholecalciferol and
calcium.Clin Sci (Lond). 1979 Feb; 56(2):157–61.)
Sato reported that two years of vitamin D treatment at 1,000 IU per day
significantly increased muscle strength, doubled mean diameter, and tripled
fast-twitch muscle fiber percentage in the functional limbs of 48 severely
vitamin D deficient, elderly stroke patients. The placebo control group suffered
declines, both in muscle strength and in fast-twitch muscle fiber size and
percentage. (Source: Sato Y, Iwamoto J, Kanoko T, Satoh K Low-Dose Vitamin D
Prevents Muscular Atrophy and Reduces Falls and Hip Fractures in Women after
Stroke: A Randomized Controlled Trial. Cerebrovasc Dis. 2005 Jul 27;
20(3):187–192 [Epub ahead of print])
These studies reveal that vitamin D stimulates growth (in size and number) of
muscle fibers critical to athletic ability in those who are vitamin D deficient.
Neuromuscular performance improves with higher vitamin D blood
levels.
I found 13 positive studies of associations between vitamin D
levels and various parameters of neuromuscular performance. However, they were
all in older people. Of course, old people can be athletes too. Furthermore, age
differences in physiology and pharmacology are quantitative, not qualitative.
That is, what is true in old people will be true in young people, although the
magnitude might be different. Higher vitamin D levels are associated with a wide
variety of athletic performance but appear to have the strongest associations
with balance, timing, and timed tests of physical performance.
The three largest studies had more than 7,000 elderly subjects. All found
evidence of a vitamin D threshold between 30–50 ng/mL, above which further
improvements in athletic performance were not seen. Wicherts and her colleagues
found a linear correlation between vitamin D and neuromuscular performance:
scores were 78% better for those with vitamin D levels greater than 30 ng/mL as
compared to those with levels less than10 ng/mL. (Sources: Bischoff-Ferrari HA,
Dietrich T, Orav EJ, Hu FB, Zhang Y, Karlson EW, Dawson-Hughes B Higher
25-hydroxyvitamin D concentrations are associated with better lower-extremity
function in both active and inactive persons aged > or =60 y. Am J Clin Nutr.
2004 Sep; 80(3):752–8. Gerdhem P, Ringsberg KA, Obrant KJ, Akesson K Association
between 25-hydroxy vitamin D levels, physical activity, muscle strength and
fractures in the prospective population-based OPRA Study of Elderly
Women.Osteoporos Int. 2005 Nov; 16(11):1425–31. Wicherts IS, et al. Vitamin D
status predicts physical performance and its decline in older persons. J Clin
Endocrinol Metab. 2007 Mar 6; [Epub ahead of print].)
Professor Heike Bischoff-Ferrari, now in Switzerland, did the largest study. She
and her colleagues found a strong positive correlation as well as a suggestion
of a U-shaped curve with athletic performance on one test. The curve peaked at
vitamin D levels of 50 ng/mL before deteriorating with higher levels. The
possibility that vitamin D levels around 50 ng/mL may be optimal for athletic
performance is intriguing, because such levels are common in humans living in a
"natural" state of sun exposure, such as lifeguards or tropical farmers.
(Source: Bischoff HA, Stahelin HB, Urscheler N, Ehrsam R, Vonthein R,
Perrig-Chiello P, Tyndall A, Theiler R Muscle strength in the elderly: its
relation to vitamin D metabolites. Arch Phys Med Rehabil. 1999 Jan; 80(1):54–8.)
Also interesting, all three studies that looked for an association between
mental abilities and vitamin D levels found one. A fourth study, unrelated to
athletic function, also found an association. The obvious explanation for these
findings is that cognitively impaired patients do not go outdoors as often as
higher functioning patients and thus have lower vitamin D levels. However, Dhesi
found the association after excluding all but mildly-demented patients, making
such an explanation more difficult. Flicker and, more recently, Przybelski and
Binkley found the association after controlling for outdoor activities, raising
the possibility that the association of vitamin D levels with cognitive
abilities is causal. Both the vitamin D receptor and the enzyme necessary to
activate vitamin D are present in a wide variety of human brain tissue. If
vitamin D deficiency impairs cognitive abilities, it is likely that such
deficiencies will also impair the brain's ability to process the complex
circuits needed for peak athletic performance. (Sources: Dhesi JK, Bearne LM,
Moniz C, Hurley MV, Jackson SH, Swift CG, Allain TJ Neuromuscular and
psychomotor function in elderly subjects who fall and the relationship with
vitamin D status. J Bone Miner Res. 2002 May; 17(5):891–7. Kenny AM, Biskup B,
Robbins B, Marcella G, Burleson JA Effects of vitamin D supplementation on
strength, physical function, and health perception in older, community-dwelling
men. J Am Geriatr Soc. 2003 Dec; 51(12):1762–7. Flicker L, Mead K, MacInnis RJ,
Nowson C, Scherer S, Stein MS, Thomas J, Hopper JL, Wark JD Serum vitamin D and
falls in older women in residential care in Australia.J Am Geriatr Soc. 2003
Nov; 51(11):1533–8. Przybelski RJ, Binkley NCIs vitamin D important for
preserving cognition? A positive correlation of serum 25-hydroxyvitamin D
concentration with cognitive function. Arch Biochem Biophys. 2007 Jan 8; [Epub
ahead of print].)
There can be no doubt that higher vitamin D levels are associated with improved
athletic performance in the elderly. From what we know of physiology and
pharmacology, the same associations should hold true in young people, including
young athletes.
4. True or False? Vitamin D has been found to improve both balance and
reaction time.
True. Eleven studies found vitamin D improved physical
performance in terms of balance and reaction time. Again, almost all the studies
were performed with older persons and none used world-class athletes. However,
there is no medical reason why vitamin D would improve the physical performance
of older people who are vitamin D-deficient but not that of younger people. One
study did use younger subjects (55 severely vitamin D deficient women) and
showed dramatic physical performance effects. (Sources: Sorensen OH, Lund B,
Saltin B, Lund B, Andersen RB, Hjorth L, Melsen F, Mosekilde L Myopathy in bone
loss of aging: improvement by treatment with 1 a-hydroxycholecalciferol and
calcium. Clin Sci (London) 1979 Feb; 56(2):157–61. Gloth FM 3rd, Smith CE,
Hollis BW, Tobin JD Functional improvement with vitamin D replenishment in a
cohort of frail, vitamin D deficient older people. J Am Geriatr Soc. 1995 Nov;
43(11):1269–71. Glerup H, Mikkelsen K, Poulsen L, Hass E, Overbeck S, Andersen
H, Charles P, Eriksen EF Hypovitaminosis D myopathy without biochemical signs of
osteomalacic bone involvement.Calcif Tissue Int. 2000 Jun; 66(6):419–24.
Prabhala A, Garg R, Dandona P Severe myopathy associated with vitamin D
deficiency in western New York. Arch Intern Med. 2000 Apr 24; 160(8):1199–203.
Verhaar HJ, Samson MM, Jansen PA, de Vreede PL, Manten JW, Duursma SA Muscle
strength, functional mobility and vitamin D in older women. Aging (Milano). 2000
Dec; 12(6):455–60. Pfeifer M, Begerow B, Minne HW, Abrams C, Nachtigall D,
Hansen C Effects of a short-term vitamin D and calcium supplementation on body
sway and secondary hyperparathyroidism in elderly women. J Bone Miner Res. 2000
Jun; 15(6):1113–8. Bischoff HA, Stahelin HB, Dick W, Akos R, Knecht M, Salis C,
Nebiker M, Theiler R, Pfeifer M, Begerow B, Lew RA, Conzelmann M Effects of
vitamin D and calcium supplementation on falls: a randomized controlled trial. J
Bone Miner Res. 2003 Feb; 18(2):343–51. Dhesi JK, Jackson SH, Bearne LM, Moniz
C, Hurley MV, Swift CG, Allain TJ Vitamin D supplementation improves
neuromuscular function in older people who fall. Age Ageing. 2004 Nov;
33(6):589–95. Sato Y, Iwamoto J, Kanoko T, Satoh K Low-Dose Vitamin D Prevents
Muscular Atrophy and Reduces Falls and Hip Fractures in Women after Stroke: A
Randomized Controlled Trial. Cerebrovasc Dis. 2005 Jul 27; 20(3):187–192 [Epub
ahead of print])
In summary, five converging—but totally separate—lines of scientific evidence
leave little doubt that vitamin D improves athletic performance. A sixth line of
evidence exists that I omitted due to its complexity: the two studies I found on
muscle strength and vitamin D receptor polymorphisms (genetic variations), both
were positive. Anyway, the scientific evidence that UVB radiation, either from
the sun or a sunbed, will improve athletic performance is overwhelming and the
mechanism is almost certainly vitamin D production. Peak athletic performance
will probably occur with 25OHD levels of about 50 ng/mL, a level that can be
obtained through the use of supplements as well.
All that is missing is a big time professional or college team identifying, and
then treating, their elite athletes who are vitamin D deficient. Can you imagine
what such performance-enhancing effects would do for basketball players, the
majority of which are black and practice and play indoors all winter? Or
gymnasts? Weight lifters? Can you imagine what it might do for those chronic
neuromuscular injuries which are so common in sports medicine?
A word of caution, though. The above studies suggest that taking too much
vitamin D (more than 5,000 IU/day) may actually worsen athletic performance. So
take the right amount, not all you can swallow. Take enough to keep your
25-hydroxyvitamin D levels around 50 ng/mL, year-round. Easier yet, regularly
use the sun in the summer and a sunbed (once a week should be about right) in
the winter—with care not to burn.
When you think about it, none of this should surprise anyone. Every bodybuilder
knows that steroid hormones can improve athletic performance and they certainly
increase muscle mass. Barry Bonds knows they increase timing and power.
Activated vitamin D is as potent a steroid hormone as exists in the human body.
However, unlike other steroids, levels of activated vitamin D in muscle and
nerve tissue are primarily regulated by sun exposure. That's right, the
rate-limiting step for the autocrine function of activated vitamin D is under
your control and depends on how much daily vitamin D you receive. It's ironic
that many athletes now avoid the sun. Organized baseball is even promoting sun
avoidance and sunblocks. The ancient Greeks knew better; they had their elite
athletes train on the beach and in the nude.
So the level of vitamin D (50 ng/mL) associated with peak athletic performance
is the very same level that recent studies show also helps to prevent cancer,
diabetes, hypertension, influenza, multiple sclerosis, major depression,
cognitive decline, etc. But who cares about all that disease stuff old people
get! We're talking about important stuff here: speed, balance, reaction time,
muscle mass and strength, squats, reps.
As for my young basketball player, guess who's now taking 4,000 IU vitamin D
a day? That's right! And his 25-hydroxyvitamin D level is now 54 ng/mL. Has this
improved his game? Well...he said to me he feels his timing is better, can jump
a little higher, run faster and...oh yeah! and that the ball feels
"sweeter"—whatever that means. #
|
