Benefits of Vitamin D: Could Vitamins Contribute To Disease Prevention?

Résultat de recherche d'images pour "Vitamin D"Vitamin D is a fat soluble vitamin that is found in food and can also be made in your body upon exposure to ultraviolet (UV) rays from the sun. When our body is exposed to the sun, UV rays from sunlight trigger synthesis of Vitamin D in the skin.

Vitamin D has long been known for its important role in mineralization of bone and in regulating the levels of calcium and phosphorus in our body. It may play a role in the prevention and/or treatment of the following health conditions: Atherosclerosis Heart Disease, Hypertension, Breast cancer, Colon cancer, Prostate cancer, Skin cancer, Mental Illness, Depression, Epilepsy, Muscle Weakness, Chronic Pain, Inflammatory bowel disease, Kidney disease, Liver disease, Multiple sclerosis, Osteoporosis, Osteoarthritis, Periodontal disease, Preeclampsia, Psoriasis, Tinnitus, Diabetes, Obesity, Ulcerative colitis.

It was originally classified in 1922 as a vitamin by a British researcher, Edward Mellanby while researching a disease called rickets.

Vitamins are defined as nutrients that are necessary for the proper functioning of the body’s tissues and organs but cannot be produced by our body. By this definition, although “Vitamin D” is essential for calcium and phosphorus metabolism in our body and is required for the normal development of healthy bones and teeth, it is produced by our body when our skin is exposed to ultraviolet rays from the sun and therefore it does not satisfy the definition of the “Vitamin”. To add to the confusion, scientists say that there are two types of Vitamin D; Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol).

The standard for measurement of Vitamin D is 25(OH)D (25-hydroxy vitamin D) and it is the best indicator of Vitamin D in our body.

Vitamin D3 (cholecalciferol) is converted from its basic building block, cholesterol, when ultraviolet rays from the sun hit the cells of our skin. Vitamin D3 must be metabolized by the liver and then by the kidneys and converted into hormonal form of Vitamin D.

Vitamin D2 is plant-based and is converted from its basic building block, ergosterol, to Vitamin D2 state when sunlight hits the leaves of the plant. It does not occur in humans and is only half as potent as D3 (cholecalciferol), does not raise serum 25(OH)D as effectively, is less bioavailable, is poorly metabolized and has shorter half-life than Vitamin D3. It is not considered equivalent to Vitamin D3 and has been associated with most of the Vitamin D toxicity.

The Institute of Medicine of the National Academy has not established an RDA (Recommended Dietary Allowances) for Vitamin D, only an AI (Adequate Intake) for otherwise healthy persons to avoid metabolic bone disease.

It was believed that 400 iu (international unit) per day was adequate. But this level turned out to be low and even 1000 iu per day was not enough for people with low level of Vitamin D to reach optimum serum level now being recommended. The 1000 iu has now become the very basic level for normal persons in addition to sunlight. Often more, to the extent of 2000 iu per day indefinitely may be needed in some cases. However, in such cases, their Vitamin D level must be tested first and then retested yearly. Individuals with osteoporosis and breast, prostate and immune health issues have greater Vitamin D needs. These individuals and those with other health concerns should consult their doctor before beginning with Vitamin regimen.

Vitamins Don’t Prevent Cancer: Scientists Conclude that Antioxidant Supplements are Ineffective

Résultat de recherche d'images pour "Cancer"A recently-completed segment of the Physicians Health Study II (PHS II) has led investigators to conclude that vitamins C and E and beta-carotene do not help prevent cancer. This pronouncement follows similar reports from other studies that B vitamins (including folic acid), vitamin D, and calcium are not useful in cancer prevention, either.

PHS II was an extension of an ongoing longitudinal trial that had already shown no benefit from vitamin C or vitamin E in the prevention of cardiovascular disease. (Sesso H. Vitamins E and C supplements not effective for prevention of cardiovascular disease in men. JAMA. 300[18]:2123-2133)

Dr. Howard Sesso, assistant professor of medicine at Brigham and Women’s Hospital and one of the study’s principal investigators, said, “…in the context of two very common outcomes—cardioprotection and chemoprevention—we see no compelling evidence to take vitamin E or C supplements.” (HealthDay News)

Physicians Health Study—Design and Outcomes

PHSII included 14,642 male physicians, all of them older than 50 years. All were pronounced “healthy” at the study’s onset, although 44% were past or current smokers, 77% were taking aspirin, 42% had a history of hypertension, 36% had a history of hypercholesterolemia, 6% were diabetic, and 5% had a history of cardiovascular disease.

The group was randomized in a multifactorial fashion to provide blinded exposure to vitamin C, vitamin E, beta-carotene, Centrum Silver multivitamin, or placebo. Vitamin C and the multivitamin (or their placebos) were taken daily. Vitamin E and beta-carotene (or their placebos) were taken every other day.

All of the vitamins used in this study were synthetic.

By the study’s end, participants experienced a total of 1,929 cases of cancer, 1,013 of which were prostate cancers. Overall risk for cancer was not statistically different in any of the groups. The study’s authors determined that this large, long-term trial demonstrated no benefit from supplemental vitamin C or vitamin E.

Limitations and Shortcomings of the Physicians Health Study

Results of PHS II cannot be extrapolated to the general population for the following reasons:

Only male physicians in the United States were included. Physicians experience a different level of access to both health care and health information—and therefore, possibly, a different risk profile—than other individuals.

Assessment of exposure (i.e., to other supplements, medications, medical care, or risks) was accomplished through a mailed questionnaire, as were some critical endpoints (i.e., cancer diagnosis). Such questionnaires are susceptible to bias.

Subjects were followed for a mean duration of eight years, but some members of the study group were retained from the previous PHS I, while others were recruited at the outset of PHS II. Thus, longitudinal exposures to vitamins varied considerably; a longer trial with simultaneous recruitment of subjects might yield different results.

Significant disagreement exists about the validity of results from studies that utilize synthetic forms of vitamins. Evidence suggests that people whose diets contain high levels of antioxidant vitamins do experience a lower overall risk for cancer and cardiovascular disease. (Byers T, Guerrero N. Epidemiologic evidence for vitamin C and vitamin E in cancer prevention. The Amer Journ Clin Nutr 1995;62(6):1385-1392)

In the end, well-designed studies may, indeed, show that supplementation with isolated vitamins is ineffective for preventing cardiovascular disease or cancer. One day we may be left with the knowledge that only a diet rich in fruits, vegetables, and grains is ultimately protective.

However, until a genuinely well-designed study is completed—one that employs vitamins from natural sources in a heterogeneous population—curious individuals are left to their musings.

How to Lose Stomach Fat: The Best Exercises

Résultat de recherche d'images pour "Stomach Fat"If you guessed that the best exercises for a flabby stomach are sit-ups and crunches, sadly you’re mistaken. Sit-ups won’t burn fat off your belly anymore than thigh exercises will slim thunder thighs, according to the American Council on Exercise. The best exercise you can do to get rid of a flabby stomach is cardio, along with adopting a healthy diet. You can target your abdomen with ab exercises, but that will only tone the muscles covered by excess body fat. To get rid of flab, daily exercise sessions of moderate to high intensity will have you saying goodbye to the fat on your stomach, and the thunder thighs.

Cardio Methods to Lose the Stomach

Walking, swimming, aerobics, spinning, sports, group exercise classes—any physical activity you do consistently works for combating belly fat. Pick an activity you enjoy and once you start, keep moving. Frequent stops cause your heart rate to slow and reduce your calorie expenditure. Cardio machines work well because you will not get stopped by traffic, weather, or other obstacles that occur when you try to exercise outdoors.

Importance of Exercise Variety

While you should pick exercises you like, you still need variety. Your body adapts to even the best exercises within three to four weeks, according to the “NASM Essentials of Personal Fitness Training” by the National Academy of Sports Medicine. This means you have to add time, distance, speed or resistance to an activity to keep burning the same calories. Instead of adding an extra mile to your run every week to get the same amount of reward, switch your cardio method monthly. Walk one month, swim the next, and bike the following month. Or switch up what you do throughout the week. For example, on Monday, Wednesday and Friday try walking. On Tuesday and Thursday, swim or take a cardio kickboxing class instead.

The Right Intensity for Fat Burning

Moderate to high intensity cardio is not only useful for losing your gut, it also increases cardiovascular fitness and endurance. You’ll also see a higher total calorie expenditure than when doing light cardio. The total calorie expenditure of your workouts is what matters most for burning fat, according to Bodybuilding4You.com. You can utilize what is called the “talk test” to measure your intensity. The talk test is a measure of exercise intensity equal in value to heart rate monitoring, according to an article by Phil Block, M.S. and Len Kraviz, Ph.D. entitled “The Talk Test.'” If you can recite the “Pledge of Allegiance,” but still feel that you’re working out then you’re exercising at a moderate intensity. If you can only get to “the United States of America” before needing to pause, you’re working at a high intensity.

The Trade Off

Although moderate intensity cardio may seem to be the best choice because it’s easier, there is a trade off: you have to exercise more to stay in shape. For general health benefits, the Centers of Disease Control and Prevention (CDC) recommend that adults engage in a minimum of 150 minutes of moderate exercise per week, which is double the recommended amount of time for high intensity exercise. So if your primary goal is to lose the tummy, longer cardio sessions at a moderate level may be best, but in the long run, building up to high intensity exercise even a couple of days a week might be better for your health.

Health Effects of Vitamin D: Vitamin D May Contribute to More than Bone Health

Résultat de recherche d'images pour "Vitamin D"Vitamins are essential components of the diet, required for cell function and growth; there are 13 essential vitamins. Vitamin D is a fat-soluble vitamin important to the maintenance of normal blood levels of calcium and phosphorus. Vitamin D aids in calcium absorption and bone growth. Vitamin D deficiency can result in softening and weakening of the bone, or osteomalacia, a condition called rickets in children. Recent studies suggest that Vitamin D may help protect against osteoporosis, hypertension, cancer, and autoimmune disease.

Recommended Vitamin D levels

Adequate Intake (AI) levels have been established by the Food and Nutrition Board at the Institute of Medicine of the National Academies; these AI levels represent the amount of Vitamin D consumed daily that will maintain bone health and normal calcium metabolism in healthy people. The AI levels established in 1997 are 200 International Units (IU) for all individuals under 50 years of age, 400 IU for people 50-70 years old, and 600 IU for those over 70. The recommended upper intake level (UL) limit has been set at 2000 IU because very high levels of Vitamin D can result in toxicity.

Dietary sources of Vitamin D

Vitamin D is found in fish, and is present in small amounts in cheese, egg yolk, and beef liver. It is also added to fortified foods, and these are the main source of Vitamin D in the American diet. Vitamin D was added to milk in the U.S. starting in the 1930s to combat rickets. It is now also added to some breakfast cereals, some dairy products, and some calcium-fortified juices.

There are two forms of Vitamin D: Vitamin D2 (ergocalciferol), which can be produced by plants and by mushrooms if they are exposed to UV light, and Vitamin D3 (cholecalciferol), which is synthesized in the skin of animals upon exposure to UV light.

Vitamin D from Sun Exposure

Upon exposure to UV radiation, 7-dehydrocholesterol in the skin is converted to previtamin D3, which then is changed into Vitamin D3. Precise guidelines for how much sun exposure is needed to produce sufficient Vitamin D are not available, but it has been estimated that 5-30 minutes of sun exposure at least twice a week is enough. It is important not to get excessive sun exposure, since UV light is also known to increase the risk of skin cancer.

Toxicity

Vitamin D toxicity can cause nausea and vomiting, and can raise the blood level of calcium which can result in confusion and heart rhythm abnormalities. Excessive levels can also increase the risk of kidney stones. Toxicity is most likely to result from taking dietary supplements, since it is difficult to obtain toxic levels of Vitamin D through the diet, unless large amounts of cod liver oil are consumed. Also, excessive sun exposure does not result in toxic levels of Vitamin D because Vitamin D is broken down as well as formed by sunlight.

Vitamin D and Disease Prevention

There is increasing evidence that Vitamin D may be protective against several other diseases besides those related to bone health. Some studies indicate a relationship between lower serum Vitamin D levels and increased colon cancer risk, increased cardiovascular disease, and increased risk of stroke. Increased intake of Vitamin D was associated with a decreased risk of autoimmune disease such as rheumatoid arthritis. All of these results are preliminary, but intriguing. Further research is required to establish the relationships between serum Vitamin D levels and measures of biological function and disease.

Vitamin Deficiency—Causes, Results and Symptoms

Résultat de recherche d'images pour "Vitamin"Vitamins are nutrients essential for good health, and perform a number of vital functions like ensuring proper metabolism and immunity. Since a deficiency of essential vitamins can have serious consequences, it is important to be aware of the causes and consequences of deficiency.

Causes of Vitamin Deficiency

Studies have shown that deficiency of vitamins like D, E, B6, B12 and folic acid is most common, and some factors are responsible for the deficiency of one or more essential vitamins. The most common cause of deficiency is a diet that is not balanced, thus lacking the required amounts of the vitamins required. For example, people who adopt a macrobiotic diet or one aimed at a weight loss program do not consume a balanced diet. Moreover, physically strenuous activities lead to a depletion of nutrient levels.

There are other factors that make some people more prone to vitamin deficiency. Those living alone, the elderly and pre and post menopausal women are more vulnerable and often suffer from the symptoms of vitamin deficiency. People living alone may neglect to cook or eat regular meals and lack a well balanced diet. A poor quality or restricted diet over a long period leads to a deficiency of vitamin B 6.

Elderly people generally go out less and have limited exposure to the sun. Moreover, they usually consume less milk, which like sunlight, is a source of vitamin D, leading to a deficiency of the vitamin. Vegetarians in this age group often have a restricted diet leading to gastrointestinal disorders, which hinders absorption of vitamin B 12. Vitamin B 12 is found mainly in non-vegetarian food and dairy products, so vegetarians, especially vegans could suffer from its deficiency. Moreover, its absorption is hindered by certain kinds of medication.

Excess consumption of alcohol leads to a decreased absorption of vitamin B6. A diet lacking in vegetables and fruits can lead to a deficiency of vitamin C, while those who do not consume milk or suffer from lactose intolerance are prone to calcium deficiency.

Results and Symptoms of Vitamin Deficiency

Vitamins are essential for health, so a deficiency causes serious problems. Certain symptoms are seen in cases of deficiency. Deficiency of vitamin A causes problems of the skin and gastrointestinal tract, retarded growth of the skeleton and night blindness.

Muscular weakness, leg cramps, digestive problems and irritability are symptoms of vitamin B1 deficiency, while weakness, low blood counts, inflammation of the tongue, mouth ulcers and dandruff are caused by lack of vitamin B2. Vitamin B3 deficiency leads to pellagra, while lowered immunity, skin problems and even mental confusion are due to lack of vitamin B6. Vitamin B5 is an antioxidant required for bodily processes, normal growth and reproduction, so depression and heart problems result from its deficiency. Lack of vitamin B12 leads to pernicious anemia.

Vitamin C deficiency causes scurvy, and lack of vitamin D results in rickets. Deficiency of Vitamin E causes weakness, as it affects the nervous system. Moreover, it leads to vision related problems and loss of muscle mass. Finally, lack of vitamin K causes gastrointestinal bleeding and easy bruising.

Vitamins perform major functions in the body, and are essential for overall good health. Deficiency is caused by factors like an inadequate or restricted diet and lack of absorption. Lack of different vitamins is manifested in symptoms like vision related problems, weakness and low immunity. Therefore, it is essential to guard against the factors that cause deficiency and recognize the symptoms.