The chemotherapy drugs, Taxol (paclitaxel) and Taxotere (docetaxel) can have a beneficial impact on survival and quality of life for many people with advanced metastatic cancers. But these drugs can also incur damage to the sensory nervous system, resulting in painful tingling or numbness in the feet and hands. So uncomfortable and stressful are these symptoms that the oncologist is often forced to reduce the dosage, thus ultimately limiting the effectiveness of the treatment. One strategy that is being used with some success is the antioxidant supplement called alpha-lipoic acid, or ALA. A number of studies have found that ALA may be effective in treating the nerve damage that afflicts people with diabetes. The supplement is referred to as the “mother of all antioxidants” because it tends to support the activities of vitamins C and E, and other antioxidants. Since free radicals are thought to be a major part of the mechanism behind the nerve damage, it makes sense that ALA might have some protective effect. The nerve-protecting benefits of ALA for diabetics seem so convincing that some oncologists have begun recommending the supplement to cancer patients. In a 2003 issue of the Annals of Oncology, researchers at the University of Vienna (Austria) presented the first-ever study of cancer patients receiving ALA to counteract the neurotoxic effects of chemotherapy drugs. Fourteen people were enrolled in the study, including six with lung cancer, five with advanced gastric cancers, and three with head and neck tumors. The nerve-damaging drugs included Taxol and cisplatin. Each of these patients had reported experiencing numbness or tingling in either their hands or feet or both, and also had reported a burning sensation after receiving the chemotherapy. All 14 patients received 600 milligrams of ALA intravenously once a week for three to five weeks. This was followed by 1800 milligrams orally (600 mg three times a day) until they recovered fully from the neuropathy. Each patient took ALA for a maximum of six months. The study’s findings seemed to support the use of this antioxidant supplement. Eight out of the fourteen patients (57%) showed a favorable response to ALA. In six patients with moderate or grade 2 nerve damage, treatment with ALA resulted in a major improvement in neurological symptoms. In two patients who suffered from severe or grade 3 nerve damage, ALA supplementation brought substantial relief of symptoms. Some patients responded rapidly to ALA (within three weeks), while others took two to three months to respond. These findings indicate that ALA, when used to counteract chemotherapy-related neuropathy, may be able to stop and reverse the nerve-damaging effects of the anticancer drugs. No major side effects were reported from taking the ALA. In other research, ALA has shown some direct anticancer activities as well. Given the wide margin of safety for this supplement, ALA may indeed be considered a promising way to protect the nervous system during chemotherapy.

Sources
Gedlicka C, Kornek GV, Schmid K, Scheithauer W. Amelioration of docetaxel/cisplatin induced polyneuropathy by alpha-lipoic acid. Ann Oncol. 2003; 14(2):339-40.

Ziegler D, Hanefeld MH, Ruhnau KJ et al. Treatment of symptomatic diabetic polyneuropathy with the antioxidant -lipoic acid. A 7-month multicenter randomized controlled trial (ALADIN III Study).
Diabetes Care 1999; 22: 1296-1301

Rock E, Demark A. Nutritional approaches to late toxicities of adjuvant chemotherapy in breast cancer survivors. J. Nutr., November 1, 2003; 133(11): 3785S - 3793

In Part 1 of this series, we explained the importance of being physically and mentally fit for cancer treatment. One might well ask, Why do health professionals often overlook the importance of exercising and getting in shape after a cancer diagnosis? There seem to be several primary reasons. To begin with, until very recently, it was assumed that getting more bed rest is the right thing to do after the diagnosis. Over the years, doctors and nurses routinely told their patients that exercise would deplete their energy levels, while bed rest would help save it. But research by Dr. Maryl Winningham and others suggests that the opposite scenario is the closer to the truth: too much rest steadily depletes one’s energy levels and further exacerbates fatigue. According to Winningham’s studies, staying in bed or sitting around watching TV after a cancer diagnosis sets up a vicious cycle. Blood circulation stagnates and this results in a less oxygen and other nutrients getting distributed throughout the body. Because oxygen and nutrients are needed to support healthy (aerobic) metabolism, the result of this stagnation is less energy and more fatigue over time, hence an increased desire to remain inactive. As the downward spiral continues, the fatigue and inertia become so extreme that the mere thought of exerting onself seems like an impossibility.

It turns out that moving the body is the antidote to this problem. By getting your heart rate up with gentle aerobic exercise, you greatly increase your capacity to perform the activities of daily living and improve your overall quality of life. Another major reason to engage your muscles after a cancer diagnosis is to help prevent the process of physical wasting that affects many individuals with advanced-stage cancers. Cancer shifts the body’s metabolism into a “breakdown” or catabolic mode, thus further increasing the muscle-degrading effects of not exercising. The loss of muscle leads to less aerobic activity, reduced endurance, and yet more immobility-another vicious cycle. The solution is to engage in gentle workouts with small weights as well as mindful, continuous weight-bearing exercise such as Tai Chi to help build and maintain the large muscles of the legs. Remember that overly strenuous exercise can damage tissue and may actually increase inflammation. It is ill-advised for anyone who is out of shape to push their bodies, especially if they have just gone through major surgery, chemotherapy, or other intensive treatments. Restorative yoga, Qigong, or the use of a TheraBand can all be immensely healing and therapeutic.

Equally essential is the targeted use of nutritional pharmacology to control the lean-tissue wasting process known as cachexia. This is a chronic low-grade inflammatory imbalance that keeps your muscles in breakdown mode. According to cachexia expert Vickie Baracos of the University of Alberta, in Edmonton, Canada, a combination of resistance exercise, omega-3s, high-quality protein and anti-inflammatories may be the key to reversing this deadly problem.

Cancer patients and cancer survivors may greatly benefit by increasing their level of physical activity and adopting a healthier, plant-based diet. People diagnosed with cancer rarely ask their oncologist whether or not they have the physical and mental “fitness” to undergo treatment. And yet, this is an entirely relevant concern. The rigors of cancer therapy are often so taxing that about one in every three individuals who undergo chemotherapy end up quitting before they have a chance to complete their treatment. A study published in the April 21, 2008 issue of the journal Cancer concluded that far too many cancer patients are overweight and out of shape. Researchers at the University of Alberta in Edmonton, Canada, analyzed data from more than 114,000 adults. They found that one in three cancer survivors was overweight, while nearly one in five was obese. Moreover, fewer than 22 percent of all cancer survivors were physically active.

Even more telling was the finding that obese breast cancer survivors were less likely to be active compared with obese women without a history of the disease. This finding is cause for concern because research has shown that obesity increases the risk of recurrence and mortality after a breast cancer diagnosis. Obese breast cancer survivors who exercise more not only may keep the disease from recurring but can also greatly improve their quality of life during and after cancer treatment. They feel better, sleep better, and have more stable moods and energy levels overall.

Another aspect of getting physically fit after a cancer diagnosis has to do with better handling the side effects of conventional cancer treatments. Intensive chemotherapy and radiotherapy can take a heavy toll on mind and body. Malnutrition, anemia (often accompanied by chronic fatigue), dehydration, infection, fever, reduced white blood cell counts are among the more common side effects that force many patients to visit the emergency rooms. For each month of chemotherapy, the chance of experiencing a major side effect increases by 20%. No small wonder, then, that so many patients end up prematurely dropping out of treatment. Here, too, the solution is to take better care of oneself - especially if you’re already out of shape. Just as you want to be nutritionally, physically and psychologically fit to undergo surgery, you want to be fit enough to handle the effects of intensive tumor-killing treatments. You want to do everything possible to maintain a strong, healthier body. If you feel that you need guidance, seek out an exercise physiologist or find a cancer rehabilitation program in your area. Interestingly, studies have shown that about half of all patients improve their dietary habits and quit smoking after a cancer diagnosis. But one out of every three either stop exercising or exercise less frequently than they had before. In one study, most patients reported having exercised prior to their diagnoses, and yet fewer than half of those same individuals kept up an exercise routine after the diagnosis. Again, overweight individuals, and those receiving both radiotherapy and chemotherapy, were least likely to resume an exercise regimen.

Around the country, cancer rehab programs are beginning to spring up to help patients get in shape before, during and after their treatments. Integrative medicine clinics are offering cancer rehab programs that include whole-body fitness training and specific nutritional strategies to offset treatment-related side effects. The best programs also provide psychological support and counseling as well. Though this integrated approach, many side effects can be greatly minimized and in some cases avoided altogether. And because nutrition and exercise are among the controllable risk factors for preventing a cancer recurrence, there’s a better chance of staying in remission after participating in such a program. In Part 2 of this article, we’ll address some of the myths that pertain to getting fit after a cancer diagnosis.

For decades we’ve known that the people living in France have among the lowest incidences of coronary heart disease in the Western world. What’s surprising is the fact that the typical French diet is relatively high in fat. This phenomenon, known as the French paradox, has long puzzled heart disease experts worldwide, and many have pointed to the high consumption of red wine in France as the main protective factor. In Part 1 of this series, however, we began to explore some equally strong explanations for the French paradox, with a focus on the 40-country study by Drs. William and Sonja Connor in the 1990s.

The Connors’ research unveiled another major dietary difference between the French and Fins: per capita consumption of vegetables was four times higher in France than in Finland. The French also ingested eight times more vegetables oils and thirty times more olives. Other research has confirmed that diets high in cereals, legumes, vegetables and vegetable oils help keep the coronary arteries from clogging up. (Perhaps just as important, we also know that the French eat smaller portions and take longer to eat their meals compared to their U.S. counterparts.)

By no means do these findings detract from the protective effects of red wine. But red wine is only one of many dietary pieces to the healthy heart puzzle. In the July 2007 issue of the European Heart Journal, researchers note that the beneficial or cardioprotective effects of red wine have mostly to do with their polyphenol content. These grape compounds, notably resveratrol, have been shown to reduce levels of oxidized LDL, dilate blood vessels, lower blood pressure, render the blood less “sticky” (via platelet de-aggregation), alter the liver’s metabolism of cholesterol, reduce inflammation, and protect the arteries and heart muscle. Red wine seems to confer its strongest heart-friendly effects in the context of a high-fat diet—so it seems wine and cheese really do go well together after all.

The Connors’ research helps illustrate the complexity of dietary factors involved in heart disease. When it comes to assessing the risks of dying from heart disease, no one nutrient or food can be singled out. Instead, one has to consider the total diet. Another classic example of how this bears out concerns the Eskimos, for whom cardiovascular disease is virtually absent, despite a diet very high in fat and cholesterol. The discrepancy most likely has to do with the fact that Eskimos traditionally get most of their fat from marine sources, namely seal, whale, and fish. These sources provide large quantities of the “good” omega-3 fatty acids, which confer numerous heart-friendly effects.

The take-home message: Vegetables, omega-3 fatty acids, and light or moderate consumption of red wine can be very good for your heart, particularly if you’re also getting regular exercise (gentle aerobics and resistance training) and getting a reprieve from the high-pressure arena of life through rest and relaxation. Eating some fat on the side is not going to kill you, though anyone with high blood lipid levels (in particular, high total cholesterol, LDL, and triglycerides) would do well to lower their fat intake for a few months while striving to get their health back on track. In addition, for many individuals, selective use of supplements such as phytosterols, garlic, resveratrol, guggul, and policosanol may further ensure a heart-friendly advantage.


© 2008, Mark N. Mead and Plum Spring Clinic

The idea that excess dietary fat begets clogged arteries—and eventually heart disease—has long been gospel among nutritionists and health food buffs. Studies of human populations the world over have shown that the more cholesterol and saturated fat people consume, the higher the death rates are due to coronary heart disease (CHD). Back in the early 1990s, Drs. William and Sonja Connor at Oregon Health Sciences University, along with Sabine Artaud-Wild and Gary Sexton, confirmed the fat-coronary connection in 40 countries, all of which had populations exceeding one million. As expected, however, two countries—France and Finland—failed to fit the pattern.

The Finnish-French paradox has puzzled scientists for decades. Of all European countries, Finland has the highest death rate from coronary heart disease, while France has the lowest—at least four times lower than that of Finland. And yet, the average per capita intake of both cholesterol and saturated fat is remarkably similar for the two countries. Scientists and lay people alike have held to the view that red wine is what protects French hearts even with all that cheese on the side. But the Connors suspected that differences in the consumption of other food factors could shed light on the paradox.

Their observations, first published in the December 1993 issue of the journal Circulation, confirmed this intuition. Though meat consumption was similar between the two countries, there were striking differences in the consumption of dairy products and plant foods. Compared to the French, the Fins consume three and one-half times more cow’s milk, butter and cheese. There also appears to be a relationship to milk protein intake, which is twice as high in the Finnish diet compared to the French diet. Previous research had shown that casein, a protein in cow’s milk, produced high cholesterol levels in animals.

The dairy connection is one reason we recommend substituting soy products for dairy products when your blood lipid levels are off kilter—for example, when you have a high total cholesterol, as well as high LDL and triglyceride levels. Though soy itself has only a very weak effect on cholesterol levels, consuming it in lieu of fatty dairy products (butter, cheese, and ice cream) while help improve your blood lipid levels. We also recommend consuming more nuts and seeds, and substituting fish for poultry and red meats as much as possible.

In Part 2 of this series, we’ll explore the other factors that are most likely to explain the French Paradox. As you will see, it’s important to think beyond the simplistic wine-and-cheese terms that have tended to dominate the debate since its inception.

Vegetables are among the only foods you can eat to your heart’s content without gaining weight and promoting illness.  That’s because, on a per-calorie basis, vegetables really pack in the nutrients you need for good health.  A mere half cup of broccoli, for example, provides 60 to 70 milligrams of vitamin C, which the body needs to neutralize harmful free radicals and keep cancer cells from turning into deadly tumors.  At the same time, brightly colored vegetables contain hundreds of different carotenoids, flavonoids, and other so-called phytochemicals, many of which have potent anti-cancer and health-promoting properties.

A half cup of even the most starchy vegetables—potatoes and squash, for instance—provides no more than 100 calories.  That’s less than the calories in a tablespoon of butter or oil.  Indeed, the butter or cream sauce you may have added in the past has many times the calories of vegetables.  The good news is that, with vegetables, it’s okay to eat all you can eat.  If you make them the core of your daily diet, your body will thank you for years to come.

Many people are getting sick these days because they’re not eating enough fresh vegetables.  Huge losses of nutrients result from milling, storage, shipping and overcooking.  For instance, spinach, lettuce and other greens suffer more than a 30 percent loss of vitamin C due to temperature changes, air movement and humidity.  Vitamins A, E and C are especially vulnerable to oxidation during storage; the loss of vitamin E due to this oxidation process may be 50 percent or more.  Vitamin E loss in freezing may be as high as 50 percent as well, and thawing of frozen foods may result in further losses.  The take-home lesson is this: eat your vegetables, but keep them as fresh and unprocessed as possible!

If you’re looking for ways to determine which vegetables will pack in the best nutritional value for your money, then consider their color.  In general, the deeper or darker the vegetable, the better its nutritional value.  Pale, small carrots, for example, have several times less vitamin A than mature, bright-orange carrots.   Dark-green leafy vegetables are, for the most part, a great deal higher in nutrients than light greens, such as iceberg lettuce.  And if it’s vitamin A you seek, go for deep-orange vegetables like carrots or winter squash.

Though these tips don’t guarantee an optimal diet, they’ll at least point you in a healthier direction.  The mix of vegetable colors also serves as a kind of positive reinforcement, since it makes your meal a feast for the eyes as well as the belly.  Adding color to your dietary plan is just one more incentive to eat well.

Many studies have shown a link between being overweight and having an increased risk of developing heart disease, stroke, cancer, and diabetes.  A new study suggests that a key factor in this equation is the body’s inflammatory potential, as measured by the C-reactive protein, or CRP.   High CRP levels indicate low-grade inflammation throughout the body.  These high CRP levels can also be a significant predictor of heart attacks, stroke, or other cardiovascular events in both men and women.

Epidemiologist Andrew Fogarty and colleagues at the University of Nottingham in the United Kingdom recently measured serum CRP and body weight in over 2400 adults, and then observed them over a nine-year period.  An increase in weight during this period was associated with an increase in CRP levels.  “This provides a mechanism that may explain some of the previously reported association of weight gain with an increased risk of both cancer and cardiovascular disease,” Fogarty and his colleagues report in the January 2008 American Journal of Clinical Nutrition.

Body fat or adipose tissue is known to secrete inflammatory chemicals and to help in regulating the blood levels of CRP concentrations.  This may explain the obese person’s penchant for chronic inflammation.  Thus, the CRP level is not only a marker of inflammation, but also seems to reflect how obese someone is—and what his or her risk of major diseases is as well.

To lower your body’s inflammatory potential, a total nutritional approach is recommended that includes major changes in dietary fat intake and the use of specific antioxidant and anti-inflammatory supplements.  Whether reducing the amount of body fat would further reinforce the effects of the nutritional program remains to be seen, but Fogart’s research suggests that losing weight and lowering one’s inflammatory potential are very closely linked.

Source:  Fogarty AW, Glancy C, Jones S, Lewis SA, McKeever TM, Britton JR.  A prospective study of weight change and systemic inflammation over 9 y.  Am J Clin Nutr. 2008 Jan;87(1):30-5.

In this third part of the vitamin D series, we’ll consider just how much supplemental vitamin D is most likely to bolster your health and help prevent cancer, osteoporosis, and other chronic diseases.   Vitamin D is naturally produced by plants as vitamin D2 and by animals (including humans) as vitamin D3.   Studies have shown that vitamin D status, as measured by your serum 25(OH)D level, is more effectively improved with vitamin D3 than with vitamin D2, and there are several well-defined biochemical reasons for this difference.  But both forms can be effective in terms of improving calcium absorption and musculoskeletal health.  Also, compared to synthetic vitamin D, these natural forms have more drawn-out effects and need not be taken daily.  Synthetic forms such as calcitriol need to be taken daily for optimal effectiveness.  In addition, whereas vitamin D supplements are relatively cheap, calcitriol and other vitamin D analog drugs can be expensive – and your insurance company may or may not provide coverage.   (On the other hand, vitamin D analogs tend to be safer for people at risk of developing a dangerous condition known as hypercalcemia; see the end of this article for a brief discussion of this issue.)

As noted in earlier parts of this series, vitamin D has been dubbed the “sunshine vitamin” because human skin synthesizes all we need – and then some – when exposed to the sun’s ultraviolet-B rays.  Indeed, the amount produced by the skin is quite high:  In non-obese white people, fully exposing the arms or legs to 15 to 20 minutes of summer sun yields a whopping 20,000 IU (black people need up to five times more exposure to achieve this degree of skin photosynthesis, since the skin pigment melanin acts as a potent sunscreen).  Thankfully, sitting in the sun for extended periods of time will not cause vitamin D toxicity because any excess amounts of vitamin are destroyed by sunlight.  Logically, then, our bodies should be able to safely tolerate much larger amounts of vitamin D3 than the 400 IU typically found in multivitamin or bone-building supplements, and recent research bears this out.

These days, most of us just just don’t get out in the sun as much as our ancestors did.  We spend far more time indoors, and yet the sunshine that comes through glass windows will not stimulate vitamin D3 synthesis.  Even if we do get outdoors on a regular basis, we then have to reckon with problems associated with getting too much sun—problems such as sunburn, accelerated aging of the skin, and a heightened risk of skin cancer, especially in fair-skinned people.  To counter these risks, we don sun-protective clothing and cover up with sunscreen, both of which block vitamin D production in the skin.

Beyond soaking up sunshine, additional amounts of vitamin D come from foods like fatty fish, eggs, and fortified milk.  Most fortified dairy products contain synthetic vitamin D2, which again may be less effective than natural vitamin D3.  Moreover, relying on fatty fish may not be a suitable way to get your vitamin D, because you’d have to consume a large amount of fish every day, and the fattier fish these days tend to contain more pollutants.

This brings us to the benefits of vitamin D3 supplements.  The original recommended daily allowance for vitamin D was set decades ago at 400 international units (IU).  This guideline is now considered to be obsolete, according to research by the Council for Responsible Nutrition.  Indeed, the best current estimates indicate that most adults should consider supplementing with five to ten times this amount, or in the range of 2,000 to 5,000 IU per day.  Dark-skinned, obese, and elderly people, or anyone with a poor vitamin D status (a serum level below 30 ng/ml), can generally start at the 5000 IU level and then eventually drop down to 1000 or 2000 IU per day.

Based on recent clinical trial evidence, Dr. Reinhold Vieth of the University of Toronto concludes that taking 5000 IU of vitamin D3 is quite safe even for elderly people.  Vieth and other experts predict that 10,000 IU will soon be the new “upper tolerable limit” or UL for vitamin D intake (the current UL is 2,000 IU for adults and 1,000 IU for infants up to one year of age).  For light-skinned people who get 10 minutes of mid-day sunshine in the summer months, the recommended amount is 1,000 to 2,000 IU per day.  Most experts agree that you can also take your week’s worth of vitamin D3 (say 15,000 to 35,000 IU) at a single time, like on a Sunday.  This makes vitamin D one of the easiest supplements to take by far.  Vitamin D3 supplements are now available in 1000 IU, 2000 IU, and 5000 IU gel capsules, and most people can benefit by starting at the higher dosage for a few months.  (Consider getting your 25(OH)D blood level checked and consulting with a health care professional before taking the higher dose.)

The only caveat about taking higher doses of vitamin D is that some individuals may be prone to a condition known as hypercalcemia (excessive calcium in the blood).  Symptoms of hypercalcemia include weakness, fatigue, somnolence, headache, anorexia, dry mouth, metallic taste, nausea, vomiting, cramps, diarrhea, muscle pain, bone pain and irritability.  If you have cancer and certain other conditions, your physician should monitor you for hypercalcemia in order to safeguard against this problem. If you do happen to become hypercalcemic, your physician will have you stop taking the supplement and then check your blood calcium level daily until it has normalized, and then twice weekly on a lower dose of vitamin D3.  Synthetic analog forms of the vitamin are safer for people at risk of developing hypercalcemia.  Lastly, people with liver and kidney disorders should consult with their physician before taking a high-dose vitamin D supplement.

A landmark scientific report has confirmed what many health experts have long feared:  Being overweight and out of shape can set the stage for getting cancer.  Though it has been known for many years that excess body fat is a major risk factor for diabetes, heart disease, stroke and early death, the link with cancer has been far sketchier – until now.

The new report titled “Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective,” was released in November 2007 by the World Cancer Research Fund (WCRF) International and the American Institute for Cancer Research (AICR). “This is the most comprehensive review of the evidence that’s ever been conducted, taking literally years of time and effort by scores of people around the world,” says Larry H. Kushi, associate director for epidemiology at Kaiser Permanente in Oakland, CA.  Kushi co-led one of the nine systematic literature review centers for the project and helped come up with the report’s main recommendations.

The WCRF/AICR research team examined over 7,000 scientific reports in all languages. The team’s findings went to an international panel that synthesized information for many different cancers to come up with the report’s main recommendations, which explain how diet, exercise, and other lifestyle factors interact and affect one’s risk of developing cancer.

The report concluded that about 40% of all cancers are linked to poor or imbalanced diet, lack of exercise, and excessive body weight.  It recommends striving to maintain a body mass index, or BMI, of between 21 and 23.  Until now, the standard recommended range has been 18.5 to 24.5.  Other recommendations include exercising moderately, and limiting consumption of alcohol, high-fat foods, and refined carbohydrates such as sugary beverages. Along with increasing vegetable intake, the report suggests replacing red meats and processed meats with poultry, fish, and eggs.

For more information, go to www.dietandcancerreport.org

WCRF/AICR Report Recommendations for Reducing Cancer Risk

1.   Be as lean as possible without becoming underweight.

2.   Be physically active for at least 30 minutes every day.

3.   Avoid sugary drinks. Limit consumption of energy-dense foods (particularly processed foods high in added sugar, low in fiber, or high in fat).

4.   Eat a variety of vegetables, fruits, whole grains, and legumes such as beans.

5.   Limit consumption of red meats (such as beef, pork, and lamb), and avoid processed meats.

6.   Limit alcoholic drinks to 2 a day for men and 1 a day for women.

7.   Limit consumption of salty foods and sodium-processed foods.

8.   Don’t use supplements to protect against cancer.

9.   Mothers should breastfeed exclusively for up to 6 months before adding other liquids and foods.

10. After treatment, cancer survivors should follow these recommendations for cancer prevention.

For most modern humans, the main source of vitamin D is sunshine, not diet.  Due to fears of developing skin cancer, many people get too little sunshine.  This results in a low or suboptimal blood level of 25-hydroxyvitamin D—the sole measure of one’s vitamin D status.  If this level is low—say, below 50 nanomoles per liter (nmol/L) — research indicates that you may be more prone to developing a host of health problems.  The classical disorder linked with vitamin D deficiency is known as osteomalacia, a painful softening of the bones.  In children, the deficiency causes the shafts of leg bones to irreversibly bow or bend, resulting in the grotesque disfigurement known as rickets.  Sunbathing or taking cod liver oil (which contains vitamin D) were eventually found to prevent rickets, which is now extremely rare, thanks mainly to the practice of fortifying dairy products with vitamin D.

But lack of the “sunshine vitamin” can also lead to various other health problems, including osteoporosis, osteopenia, heart disease, hypertension, diabetes, osteoarthritis, joint problems, muscle weakness, multiple sclerosis, Type 1 diabetes, mental illness and yes, many types of cancer as well.  Let’s take a quick look at what science is telling us about the connections between vitamin D and these various disorders.

Osteoporosis and Osteopenia.  When you’re lacking in vitamin D, you’re more prone to developing osteoporosis, osteopenia, and osteomalacia (as mentioned above), and your risk of experiencing a fracture increases.  Recent research indicates that achievement of optimal blood vitamin D levels (60 to 70 nmol/L) is essential for boosting bone mineral density and maximizing bone strength.  These days, vitamin D is increasingly given to elderly people with osteoporosis, particularly those being treated with bisphosphonates.  The most widely recommended dose is 800 IU with or without calcium (1,200 to 1,500 mg per day).  Sometimes vitamin D supplementation has to occur at a substantially higher dosage level (4000 to 5000 IU per day) in order to truly improve the blood levels of 25 hydroxy vitamin D.  In other words, the same dose of vitamin D is not appropriate for everyone, which is why you may need expert supervision to find the dose that’s ideal for you.

Cancer.   People living in colder climates not only experience more bone thinning with age but also have higher rates of various cancers.   These individuals tend to spend more time indoors, so they get less sun exposure. It’s also interesting to note that cancer mortality rates tend too be lowest in the summer, when vitamin D levels are highest.   Laboratory studies indicate that high-dose vitamin D may help block the growth of cancers of the breast, colon, rectum, prostate, lung and head/neck region, as well as lymphoma, leukemia and multiple myeloma.  Generally, the lower one’s overall sun exposure and vitamin D intake, the greater the risk of developing and dying from cancer.   In a five-year clinical trial conducted out of Creighton University in Nebraska, women who regularly took 2000 IU of vitamin D3 showed a 77% reduction in cancer rates compared to women taking a placebo pill, as reported in the June 2007 issue of the American Journal of Clinical Nutrition.  This 2000 IU level of vitamin D3 has also been shown to reduce PSA levels in men with prostate cancer.  This dose is five times greater than the current RDA, but it’s also the dose that many scientists now believe is optimal for adults.

One other key application concerns cancer treatment. Vitamin D has a synergistic effect against malignant disease when combined with several kinds of anti-cancer drugs, including the taxanes (Taxol and Taxotere), platinum compounds (e.g., cisplatin), dexamethasone, tamoxifen, and mitoxantrone.  Soy isoflavones, too, seem to synergize with vitamin D in combating cancer.  Finally, there’s good evidence that vitamin D can be very effective in slowing down the breakdown of bone and lessening bone pain in patients with advanced cancers.

Obesity and Metabolic Syndrome

Vitamin D is fat soluble and therefore stored in fatty tissue.  This explains why obese people have a greater capacity to store the vitamin; however, obese people have been shown to produce about half the vitamin D produced by people normal weight people when exposed to the same amount of sunshine.   Moreover, the vitamin D in those who are lean is more available for the body’s metabolic needs than in those who are obese.  In a 2007 report for Clinical Nutrition, about half of all morbidly obese individuals were found to be vitamin D deficient.  Those with the lowest levels of vitamin D had the greatest risk for the so-called metabolic syndrome.  (The latter condition includes the presence or more of the following factors: excess abdominal fat, elevated triglyceride levels, low HDL cholesterol, elevated blood pressure, and elevated fasting glucose and insulin levels.)

Cardiovascular Disease and High Blood Pressure

Vitamin D deficiency has been linked with a greater risk of cardiovascular disease and high blood pressure, according to a 2007 issue of the Archives of Internal Medicine.  But whether supplementing with extra vitamin D actually protects against cardiovascular disease remains to be seen.

Autoimmune Diseases

Lack of vitamin D has been linked with multiple sclerosis, rheumatoid arthritis, type I diabetes, lupus, and Crohn’s disease.  For example, babies deficient in vitamin D may have a greatly increased risk of developing type I diabetes by age 30 compared to those who are not deficient.  Animal studies suggest that a vitamin D supplement will greatly impede the development of type I diabetes in susceptible individuals.

Colds and Flus

Sharply reduced levels of vitamin D, due to the low intensity of solar UV radiation, may have some connection to the increased occurrence of colds and flus in the winter. Scientists have found that people with low vitamin D levels are less capable of fighting off infections, and that supplementing with vitamin D boosts resistance to colds and flus.

The problems just mentioned are only the tip of the proverbial iceberg.  Adequate levels of vitamin D may also help avert the following conditions, just as insufficient levels have been shown to fuel them: mood disorders (e.g., depression), autism, muscle weakness, periodontal disease, unexplained bone and muscle pain, infertility, mental illness, preeclampsia, cystic fibrosis, psoriasis, and age-related cognitive decline.  In Part 3 of this article, we’ll discuss how much of the vitamin you need and in what form.