Archive for the 'Osteoporosis / Bone Health' Category
October 10th, 2008 -- Posted in Osteoporosis / Bone Health, Physical Health |
RIVERSIDE, Calif. – Essential for life in higher animals, vitamin D, once linked to only bone diseases such as rickets and osteoporosis, is now recognized as a major player in contributing to overall human health, emphasizes UC Riverside’s Anthony Norman, an international expert on vitamin D.
In a paper published in the August issue of the American Journal of Clinical Nutrition, Norman identifies vitamin D’s potential for contributions to good health in the adaptive and innate immune systems, the secretion and regulation of insulin by the pancreas, the heart and blood pressure regulation, muscle strength and brain activity. In addition, access to adequate amounts of vitamin D is believed to be beneficial towards reducing the risk of cancer.
Norman also lists 36 organ tissues in the body whose cells respond biologically to vitamin D. The list includes bone marrow, breast, colon, intestine, kidney, lung, prostate, retina, skin, stomach and the uterus.
According to Norman, deficiency of vitamin D can impact all 36 organs. Already, vitamin D deficiency is associated with muscle strength decrease, high risk for falls, and increased risk for colorectal, prostate and breast and other major cancers.
“It is becoming increasingly clear to researchers in the field that vitamin D is strongly linked to several diseases,” said Norman, a distinguished professor emeritus of biochemistry and of biomedical sciences who has worked on vitamin D for more than 45 years. “Its biological sphere of influence is much broader than we originally thought. The nutritional guidelines for vitamin D intake must be carefully reevaluated to determine the adequate intake, balancing sunlight exposure with dietary intake, to achieve good health by involving all 36 target organs.”
Vitamin D is synthesized in the body in a series of steps. First, sunlight’s ultraviolet rays act on a precursor compound in skin. When skin is exposed to sunlight, a sterol present in dermal tissue is converted to vitamin D, which, in turn, is metabolized in the liver and kidneys to form a hormone. It was Norman’s laboratory that discovered, in 1967, that vitamin D is converted into a steroid hormone by the body.
The recommended daily intake of vitamin D is 200 international units (IU) for people up to 50 years old. The recommended daily intake of vitamin D is 400 IU for people 51 to 70 years old and 600 IU for people over 70 years old. Norman’s recommendation for all adults is to have an average daily intake of at least 2000 IU.
“To optimize good health you must have enough vitamin D,” he said. “Vitamin D deficiency is also especially of concern in third world countries that have poor nutritional practices and religious customs that require the body to be covered from head to toe. Ideally, to achieve the widest frequency of good health by population, we need to have 90 percent of the people with adequate amounts of vitamin D.”
About half of the elderly in North America and two-thirds of the rest of the world are not getting enough vitamin D to maintain healthy bone density, lower their risks for fracture and improve tooth attachment.
“There needs to be a sea change by various governmental agencies in terms of the advice they present to citizens about how much vitamin D should be taken,” Norman said. “The tendencies of people to live in cities where tall buildings block adequate sunlight from reaching the ground, to spend most of their time indoors, to use synthetic sunscreens that block ultraviolet rays, and to live in geographical regions of the world that do not receive adequate sunlight all contribute to the inability of the skin to biosynthesize sufficient amounts of vitamin D.”
Found in minute amounts in food, vitamins are organic substances that higher forms of animals need to grow and sustain normal health. Vitamins, however, are not synthesized in sufficient amounts to meet bodily needs. Therefore, the body must acquire them through diet or in the form of supplements.
Because it is found in very few foods naturally, milk and other foods (often orange juice) are fortified with vitamin D.
While deficiency of vitamin D impacts health negatively, ingestion of extremely high doses of vitamin D can cause hypercalcemia, a condition in which the blood’s calcium level is above normal. The highest daily ‘safe’ dose of vitamin D is 10,000 IU.
“More than ever we need to increase the amount of research on vitamin D, with more funding from government agencies and pharmaceutical companies, to meet the challenge of preserving or improving the health of everyone on the planet,” Norman said.
Norman is the recipient of many awards and honors, including the Ernst Oppenheimer Award from the Endocrine Society; the Mead Johnson Award and the Osborne and Mendel Award from American Institute of Nutrition; and the William F. Neuman Award from the American Society of Bone & Mineral Research. He is a fellow of the American Association Advancement Science as well as the American Society for Nutritional Sciences.
A grant he received in the late 1960s from the National Institutes of Health to study vitamin D has been renewed consecutively for 41 years, totaling more than $9 million.
Source: http://www.info.ucr.edu/cgi-bin/display.cgi?id=1938
Related Blogs
August 18th, 2008 -- Posted in Brain Food, Life Extension, Osteoporosis / Bone Health, Physical Health |
Researchers at Johns Hopkins are reporting what is believed to be the most conclusive evidence to date that inadequate levels of vitamin D, obtained from milk, fortified cereals and exposure to sunlight, lead to substantially increased risk of death.
In a study appearing in the Archives of Internal Medicine online Aug. 11, the Johns Hopkins team analyzed a diverse sample of 13,000 initially healthy men and women participating in an ongoing national health survey and compared the risk of death between those with the lowest blood levels of vitamin D to those with higher amounts. An unhealthy deficiency, experts say, is considered blood levels of 17.8 nanograms per milliliter or lower.
Of the 1,800 study participants known to have died by Dec. 31, 2000, nearly 700 died from some form of heart disease, with 400 of these being deficient in vitamin D. This translates overall to an estimated 26 percent increased risk of any death, though the number of deaths from heart disease alone was not large enough to meet scientific criteria to resolve that it was due to low vitamin D levels.
Yet researchers say the finding does highlight a trend, with other studies linking shortages of vitamin D to increased rates of breast cancer and depression in the elderly. And earlier published findings by the team, from the same national study, have established a possible tie-in, showing an 80 percent increased risk of peripheral artery disease from vitamin D deficits.
Researchers note that other studies in the last year or so in animals and humans have identified a connection between low levels of vitamin D and heart disease. But these studies, they say, were weakened by small sample numbers, lack of diversity in the population studied and other factors that limited scientists’ ability to generalize the findings to the public at large.
“Our results make it much more clear that all men and women concerned about their overall health should more closely monitor their blood levels of vitamin D, and make sure they have enough,” said study co-lead investigator Erin Michos.
“We think we have additional evidence to consider adding vitamin D deficiency as a distinct and separate risk factor for death from cardiovascular disease, putting it alongside much better known and understood risk factors such as age, gender, family history, smoking, high blood cholesterol levels, high blood pressure, lack of exercise, obesity and diabetes,” she said.
Vitamin D is well-known to play an essential role in cell growth, in boosting the body’s immune system and in strengthening bones.
“Now that we know vitamin D deficiency is a risk factor, we can better assess how aggressively to treat people at risk of heart disease or those who are already ill and undergoing treatment,” said Michos, who added that test screening for nutrient levels is relatively simple. It can, she said, be made part of routine blood work and be done while monitoring other known risk factors, including blood pressure, glucose and lipid levels.
Heart disease remains the nation’s leading cause of death, killing more than a million Americans each year. Nearly 10 percent of those with the condition have not one identifiable, traditional risk factor, which the experts say is why a considerable extent of the disease goes unexplained.
Michos, an assistant professor at the Johns Hopkins University School of Medicine and its Heart and Vascular Institute, recommends that people boost their vitamin D levels by eating diets rich in such fish as sardines and mackerel, consuming fortified dairy products, taking cod-liver oil and vitamin supplements and in warmer weather briefly exposing skin to the sun’s vitamin D — producing ultraviolet light.
Aware of the cancer risks linked to too much time spent in the sun, Michos says that as little as 10 to 15 minutes of daily exposure to the sun can produce sufficient amounts of vitamin D to sustain health. The hormonelike nutrient controls blood levels of calcium and phosphorus, essential chemicals in the body.
Michos says that if vitamin supplements are used, there is no evidence that more than 2,000 international units per day do any good. Study results show that heart disease death rates flattened out in participants with the highest vitamin D levels (above 50 nanograms per milliliter of blood), signaling a possible loss of the vitamin’s protective effects at too-high doses.
The U.S. Institute of Medicine suggests that an adequate daily intake of vitamin D is between 200 and 400 international units (or blood levels nearing 30 nanograms per milliliter). Previous results from the same nationwide survey showed that 41 percent of men and 53 percent of women are technically deficient in the nutrient, with vitamin D levels below 28 nanograms per milliliter.
Michal Melamed, study co-lead investigator, who started the research as a clinical fellow at Johns Hopkins, says that no one knows yet why or how vitamin D’s hormonelike properties may protect the heart, but she adds that there are plenty of leads in the better known links the vitamin has to problems with muscle overgrowth and high blood pressure, in addition to its control of inflammation, which scientists are showing plays a stronger role in all kinds of heart disease. But more research is needed to determine the nutrient’s precise biological action.
Researchers say their next steps are to test various high doses of vitamin D to find out if the nutritional supplementation results in fewer deaths and lower incidence of heart disease, including heart attack or moments of prolonged and severe chest pain.
The team also plans to investigate what biological triggers, such as obesity or hypertension, might offset or worsen the action of vitamin D on heart muscle, or whether vitamin D sets off some other reaction in the heart.
Melamed says that because vitamin D levels are known to fluctuate in direct proportion with daily physical activity, the growing epidemic of obesity and indoor sedentary lifestyles lend more urgency to act on the vitamin D factor.
Funding for this study was provided by the National Institutes of Health, P.J. Schafer Cardiovascular Research Fund and Paul Beeson Physician Faculty Scholars in Aging Program. Michos has received previous consulting fees from vitamin D therapeutics manufacturer Abbott Pharmaceuticals. The terms of these arrangements are being managed by The Johns Hopkins University in accordance with its conflict of interest policies.
Other Johns Hopkins researchers involved in this study, conducted solely at Johns Hopkins, were Wendy Post and Brad Astor. Melamed is now an assistant professor at the Albert Einstein College of Medicine of Yeshiva University.
Source: John Hopkins Medicine, David March (http://www.jhu.edu/~gazette/2008/18aug08/18vitamind.html)
August 15th, 2008 -- Posted in Arthritis / Joint Pain, Life Extension, Osteoporosis / Bone Health, Physical Health |
Jogging regularly into old age may have more benefits than a simple runner’s high — the healthy habit may slow the effects of aging, according to a Stanford study two decades in the making.
In 1984, Emeritus Prof. of Medicine James Fries came up with a hypothesis called Compression of Morbidity, which holds that healthy lifestyles will not only prolong survival, but will also decrease the number of years with disability. He gathered a team of researchers and began his experiment.
The study started with around 1,000 people over the age of 50. Half of the participants were members of a runner’s club, and the other half were otherwise healthy people from Stanford, but not members of the running club. For 21 years up until 2005, the participants rated their disability status on a scale of 0 (no severe health problems at all) to 3 (pretty much unable to do most things).
“Everybody reported increasing disability as they get older, especially since we’re talking about people who were around 60 when they started,” said Prof. of Medicine Eliza Chakravarty. “However, we found that over time, the runners group had very low levels of disability that increased very slowly. The controls, on the other hand, had disability that increased much more quickly. At the end of the study, the difference between the disability levels was very dramatic.”
Participants who were part of a runner’s club also enjoyed lower mortality rates — about half that of the non-participants.
“So not only were they less disabled, but they lived longer as well,” Chakravarty said of the running participants.
One difficulty in this study was getting rid of self-selection bias — the possibility that factors other than running contributed to the experimental results. According to Fries, it was a highly plausible explanation that a positive, healthy attitude — rather than running — produced better outcomes. The research team tried to minimize the self-selection bias in several ways.
“We statistically adjusted for many factors such as obesity and age,” Chakravarty said. “We also chose pretty healthy people in our control group. They were not obese, had normal body weight, had the same education levels as the runners and didn’t drink or smoke much. We tried to restrict it so that the main difference between the two groups was running.”
The basic message of the study, however, is simple: Exercising, at any age, is very important.
“People shouldn’t be discouraged from exercising because they’re older,” Chakravarty said. “Adopting an exercising program — even in the 50s or 60s will be beneficial down the road. We’re just really excited that we’re able to show benefits of exercise, not only in living longer, but living healthier up into the 80s.”
Of course, swimmers, bikers and other exercise fiends need not fret over the study’s emphasis on running; other forms of cardiovascular exercise serve a similar purpose.
“We think it’s probably vigorous exercise in general [that produce these results],” Chakravarty said. “Even though we chose the groups for running and non-running, we don’t necessarily think that there is anything specific to running — that running is better than cycling or swimming or any other form of regular aerobic exercise.”
Source:The Stanford Daily, Melanie Kim (http://daily.stanford.edu/article/2008/8/14/studyFindsExerciseKeyToAgingWellLivingLong)
August 13th, 2008 -- Posted in Arthritis / Joint Pain, Life Extension, Mental Health, Osteoporosis / Bone Health |
The University of Illinois at Chicago will receive $4.25 million over the next five years for research on aging individuals with disabilities, and the award will be partially matched by Special Olympics International.
UIC’s Rehabilitation Research and Training Center on Aging with Developmental Disabilities (RRTC) will start receiving its money on October 1 from the National Institute on Disability and Rehabilitation Research (NIDRR), which is part of the U.S. Department of Education.
“This new funding that starts in October is going to build on [our previous research] but it has more of a lifespan focus,” said professor and head of RRTC, Tamar Heller, Ph.D. She added that not much research has been done on adults with intellectual and developmental disabilities.
The UIC center received a similar grant in 2003, according to a spokesman from the Department of Education.
The RRTC received the grants in 2003 and in 2008 due to its well-received proposals in peer review and the progress it made in its activities, he said.
One out of the seven studies that will make use of the grant money will also use health screening data collected from athletes participating in the Special Olympics, a project partner with RRTC.
“The Special Olympics does screenings for thousands of people around the world and we’re going to be working with them to look at some of that screening data,” Heller said.
Heller and her research team will use this data to determine, over time, what risks or secondary conditions people with disabilities have that may be related to their disability. For example, Heller explains that individuals with Down’s syndrome have a higher propensity for osteoporosis.
“The Special Olympics population is very much a convenience sample for UIC,” said Special Olympics’ senior vice president for constituent services and support, Stephen Corbin. He agrees with Heller that more research needs to be done on adults with disabilities, especially in terms of what risk factors and environmental variables affect overall health.
So for the next several years, RRTC will use Special Olympic athletes’ health screening data to track long-term health trends.
“It’s one thing to show something in a lab or a clinic, but we will want to show how to improve lives in the real world,” Heller said.
Source: MedIll NorthWestern University, Elyse Russo (”http://news.medill.northwestern.edu/chicago/news.aspx?id=97197“)
July 23rd, 2008 -- Posted in Arthritis / Joint Pain, Osteoporosis / Bone Health, Physical Health |
Patients suffering from severe arthritis now have an option for total ankle replacement that offers increased mobility and pain relief without permanent metal implants. Pioneered by Daniel K. Lee, D.P.M., F.A.C.F.A.S., at UC San Diego Medical Center, this technique is the first in the U.S to offer arthritis sufferers a non-metal, biological ankle replacement.
“Up until now, patients have had two options for replacing their ankle joints: metal implants or fusion of the joints,” said Lee, director of foot and ankle surgery at UCSD Medical Center. “Now there is an option that actually restores the ankle with an FDA-approved biologic material that is similar to the collagen found in cartilage.”
During a two hour minimally-invasive surgical procedure, Lee, a podiatric foot and ankle surgeon, removes the damaged cartilage around the ankle joint through a four centimeter incision. The collagen material is then molded into the joint where it adapts to the contour of the patient’s ankle.
“Unlike a metal device, the advantage to this material is that the implant can be customized in size and contour for every patient’s individual need,” said Lee. “No matter how the patient’s ankle is shaped, the collagen is a perfect fit.”
The biologic material, processed from either human or animal collagen sources, has been used for more than 10 years in plastic and abdominal surgery and heart valve replacement. Since it is non-allergenic and sterile in nature, there is no risk of rejection or need for the patient to take immunosupressors.
To allow the material to integrate fully with the ankle joint, a temporary external device is used to stabilize the joint area while keeping it “distracted” or open for a period of 4-6 weeks. Attached by small pins, the cylinder-shaped device serves as a shock system to keep the joint free from friction and movement until healing is complete. The device is then removed entirely, which keeps the patient’s ankle free from any metal parts.
“Within 3 weeks after surgery, we see an incorporation of tissue onto the damaged cartilage,” said Lee. “The idea here is to avoid fusion of the ankle and to add longevity to the joint. We want to give patients as much mobility as possible so they can get back to the activities they love the most.”
Lee’s patient’s range in age from 30-85. Robert Adams, 82, a retired professor, received the ankle replacement after repeated attempts at physical therapy.
“My ankle collapsed on me,” said Adams. “I didn’t like the idea of a fusion with no motion or opening up my ankle for a metal device. Following this surgery, I no longer have sharp or stabbing pains. I am continuing to improve and can get around better.”
For years, patients have had the option of total joint replacement in the hips, knees, and ankle with titanium and other metal devices. While the implants are well suited for hips and knees, metal replacements for the ankle show a high level of failure and unwanted complications such as metal collapse and breakage. Once an ankle is replaced with metal, options for revision surgery are little to none.
According to the Centers for Disease Control, an estimated 46 million U.S. adults, approximately 1 in 5, report doctor-diagnosed arthritis. As the U.S. population ages, these numbers are likely to increase sharply. The number of adults with arthritis is projected to increase to 67 million by 2030, and a good proportion of U.S. adults will have limited activity as a result. Nearly two-thirds of people with arthritis are younger than 65.
This novel technique for ankle replacement and results of a study will be described in late 2008 in the Journal of Foot & Ankle Surgery.
Next »
