Because of injuries in the springtime, I missed six Boston Marathons back in the 1960s. It wasn’t until 40 years later that I found the cause: my vitamin D3 blood level was 20 nmol/l (normal is greater than 75 nmol/L, equal to 30 ng/ml). Recently I moved to Florida and have been relatively injury free for the first time in my life. I now know that people genetically susceptible to vitamin D deficiency are the ones most likely to suffer muscle weakness, injuries and poor athletic performance. Many exercisers and even competitive athletes are vitamin D deficient even if they live in the sunbelt. I believe that sunlight offers benefits that cannot be obtained just by taking vitamin D pills.
Vitamin D acts directly on specific receptors in muscles to make them stronger and prevent injury (Scandinavian Journal of Medicine & Science in Sports, April 2010). As people age, they become increasingly susceptible to muscle weakness and falls caused by lack of vitamin D. Muscles are made of thousands of individual fibers that are classified into two types: slow twitch fibers that govern endurance, and fast twitch fibers that govern primarily strength and speed. Vitamin D specifically maintains the function of the fast twitch strength fibers. A review of the world’s literature showed that lack of vitamin D is associated with muscle weakness in older people (Molecular Aspects of Medicine, June 2005). With aging, you lose muscle fibers. For example, the vastus medialis muscle in the front of the upper leg has 800,000 fibers in a 20 year old, but only 250,000 in a 60 year old. Vitamin D slows this loss of muscle fibers, preserves muscle strength and helps to prevent falls, while lack of vitamin D increases loss of fibers, muscle weakness and falls (Pediatric Clinics of North America, June 2010).
If you suffer muscle weakness, pain or injuries:
• Check your vitamin D3 level. That is the only available dependable test. If it is below 75 nmol/L (30 ng/ml), you are deficient.
• You can try taking vitamin D3 at a dose of at least 2000 IU/day for a month.
• If that does not bring your D3 level to normal, you can check with your doctor about taking higher doses.
• A certain percentage of people will have their vitamin D3 levels go above a normal 75 nmol/L and still suffer from muscle weakness, fatigue, pain and injuries.
• These people may benefit from exposure to sunlight.
• Since skin cancer is caused by cumulative exposure to sunlight over a lifetime, you should restrict exposure to sunlight on your head, face, top of ears, arms and hands.
• Try exposing your legs and bathing trunk areas. Be careful to avoid sunburn.
• Start at low exposures of less than a couple of minutes and work up gradually. You cannot tell that you have suffered a sunburn until the next day when your skin will burn, itch and perhaps blister.
Dear Dr. Mirkin: Last week you told us about the dangers of sitting for long periods; what can I do when my job requires this?
I received many emails from readers frightened by my article reporting that prolonged sitting shortens lives . I tried to show that this data apply primarily to people who do not exercise intensely. A high rise in blood sugar damages cells throughout your body. Casual exercise controls blood sugar levels for up to 17 hours. However, intense exercise may be more effective than less intense exercise in controlling high rises in blood sugar levels.
The latest literature show that intense exercise is more effective in promoting health than casual exercise; several references are listed in the last question of the July 18, 2101 eZine. You can counteract the effects of sitting if you are a competitive athlete or an intense exerciser. Sitting helps you recover faster from intense workouts than walking. Take a hard workout which damages your muscles, feel sore on the next day, and then get off your feet as much as possible. Exercise at a low intensity level for as many days as it takes for the soreness to go away, and then take your next intense workout. Try to exercise intensely three times a week. When you are training at that level, you need to get off your feet as much as possible just to recover from your intense workouts. However your muscles will be stronger if you exercise at very low intensity the other four days.
I believe that people who exercise intensely have to spend a lot of time sitting or lying down just to recover from their intense exercise. Sitting after intense exercise hastens recovery so they can take their next intense workout sooner. Not getting off their feet and not sitting for prolonged periods will increase their chances for injury. This means that you can use your sedentary job to your advantage for your training program. Caution: Intense exercise can cause heart attacks in people who already have blocked arteries.
Dear Dr. Mirkin: How do you treat muscle pain from statin pills?
Statins are drugs to lower cholesterol. More than ten percent of people who take them suffer muscle pain, and they can also decrease muscle strength and endurance. The more and the harder you exercise, the more likely you are to suffer muscle pain from taking statin drugs. You increase risk for muscle pain with higher doses and taking other drugs with statins. Coenzyme Q10 and vitamin D have been used to prevent and treat statin muscle pain, but most people taking these pills still have muscle pain.
The people most likely to suffer statin-induced muscle pain have vitamin D3 levels below 32ng/ml (Translational Research, January 2009). The most effective treatments are to stop the medication, use lower doses, use them every other day or twice a week, and raise low vitamin D3 levels to at least 30 ng/ml, equal to 75 nmol/L (Current Atherosclerosis Reports, published online July 14, 2010). Check with your doctor.
Sports medicine doctor, fitness guru and long-time radio host Gabe Mirkin, M.D., and his wife, nutritionist Diana Mirkin bring you news and tips for your healthful lifestyle. A practicing physician for 50 years more
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