So, with Roger Clemens stating that the only thing he has injected into his body is vitamin B12 (with lidocaine), I wondered if there are any performance-enhancing benefits from using the substance. And if there are, should we seek a ban (although, I think it would be nearly impossible to police)?
Once again, we have a substance that players are taking that appears to do nothing for healthy individuals. First, from the NY Times article:
In a telephone interview Thursday, Dr. Jerome Groopman, a hematologist and professor at Harvard Medical School, described lidocaine as a common local anesthetic whose injectable form would probably require a prescription. Groopman said that vitamin B12, which does not require a prescription, is administered to patients with a serious deficiency of the vitamin, usually the elderly, and that its value as an energy enhancer was “an urban legend.”
“For someone like Roger Clemens, who certainly looks robust, the likelihood that he would be deficient in vitamin B12 is a stretch,” Groopman said, noting that he had not seen Clemens’s medical records. “It would have no physiological effect. It would only have a placebo effect.”
Here are some results from a quick PubMed search.
Vitamin supplementation and athletic performance
International Journal for Vitamin and Nutrition Research, Suppl. 1989;30:163-91
Vitamins serve primarily as regulators of metabolic functions, many of which are critical to exercise performance. Depending upon the nature of their sport, e.g., strength, speed, power, endurance, or fine motor control, athletes may use megadoses of various vitamins in attempts to increase specific metabolic processes important to improved performance. Surveys have indicated that most elite athletes do take vitamin supplements, often in dosages greater than 50-100 times the United States Recommended Dietary Allowances. The theoretical basis underlying the use of each vitamin depends upon its specific metabolic function in relation to sport. Vitamin A functions to maintain night vision; thiamin, riboflavin, niacin, and pantothenic acid are all involved in muscle cell energy metabolism; niacin may also block free fatty acid release; pyridoxine is involved in the synthesis of hemoglobin and other oxygen transfer protein; folic acid and vitamin B12 are integrally involved in red blood cell (RBC) development; vitamins C and E are antioxidants, possibly preventing the destruction of the red blood cell membrane during exercise; vitamin D may be involved in muscle cell energetics through its influence on calcium. These are but a few of the possible metabolic functions of vitamins which have been suggested to have ergogenic applications to sport. Research has shown that a vitamin deficiency impairs physical performance. If this deficiency is corrected, performance usually improves. In general, vitamin supplementation to an athlete on a well-balanced diet has not been shown to improve performance. However, additional research with certain vitamins appears to be warranted, such as with the vitamin B complex and fine motor control, and with vitamin E and endurance at high altitudes. Moreover, research with megadose supplementation may also be necessary.
Vitamin and mineral status: effects on physical performance
Nutrition 2004 Jul-Aug;20(7-8):632-44
Public health recommendations encourage the selection of a balanced diet and increasing physical activity to foster health and well-being. Whereas the adverse effects of restricted intakes of protein, fat, and carbohydrate on physical performance are well known, there is limited information about the impact of low intakes of vitamins and minerals on the exercise capacity and performance of humans. Physically active people generally consume amounts of vitamins and minerals consistent with the recommendations for the general public. However, when intakes are less than recommendations, some noticeable functional impairments occur. Acute or short-term marginal deficiencies, identified by blood biochemical measures of vitamin B status, had no impacts on performance measures. Severe deprivation of folate and vitamin B12 result in anemia and reduce endurance work performance. Evidence of vitamin A and E deficiencies in athletic individuals is lacking apparently because body storage is appreciable. In contrast to vitamins, marginal mineral deficiencies impair performance. Iron deficiency, with or without anemia, impairs muscle function and limits work capacity. Magnesium deprivation increases oxygen requirements to complete submaximal exercise and reduces endurance performance. Use of vitamin and mineral supplements does not improve measures of performance in people consuming adequate diets. Young girls and individuals participating in activities with weight classifications or aesthetic components are prone to nutrient deficiencies because they restrict food intake and specific micronutrient-rich foods. This information will be useful to professionals who counsel physically active people and scientific groups who make dietary recommendations to improve health and optimize genetic potential.
UPDATE: My exercise physiologist colleague John McLester had this to say when I asked him about the ergogenic effects of B12.
Coaches as far back as I can remember have been
convincing their athletes to take B12 (our high school coach lined us up
every year for a megadose injection of B12; he was highly uneducated in
this area). They always say “it will give you energy”. The fact is B12
is used in the metabolic reactions that break down foods to make ATP
(energy). However, it will not “give you energy” since it contains no
calories. And it will not speed up those metabolic reactions unless you
are deficient. Actually, the major side effect of B12 deficiency is
pernicious anemia. Since anemia will make you feel tired all the time,
an ergogenic fallacy is born. By the way, the most likely population
susceptible to B12 deficiency is strict vegans because B12 is usually
found only in animal foods , not veggies (other than mushrooms if you
count those as veggies).
Further Update: David Pinto puts his biochemistry major to good use to discuss the possible effects of vitamins.