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Posts Tagged ‘vitamin d’

Vitamin D: New way to treat heart failure?

Strong bones, a healthy immune system, protection against some types of cancer: Recent studies suggest there’s yet another item for the expanding list of vitamin D benefits. Vitamin D, “the sunshine vitamin,” keeps the heart, the body’s long-distance runner, fit for life’s demands.

University of Michigan pharmacologist Robert U. Simpson, Ph.D., thinks it’s apt to call vitamin D “the heart tranquilizer.”

In studies in rats, Simpson and his team report the first concrete evidence that treatment with activated vitamin D can protect against heart failure. Their results appear online ahead of print in the Journal of Cardiovascular Pharmacology.

In the study, treatments with activated vitamin D prevented heart muscle cells from growing bigger – the condition, called hypertrophy, in which the heart becomes enlarged and overworked in people with heart failure. The treatments prevented heart muscle cells from the over-stimulation and increased contractions associated with the progression of heart failure.

About 5.3 million Americans have heart failure, a progressive, disabling condition in which the heart becomes enlarged as it is forced to work harder and harder, making it a challenge even to perform normal daily activities. Many people with heart disease or poorly controlled high blood pressure go on to experience a form of heart failure called congestive heart failure, in which the heart’s inability to pump blood around the body causes weakness and fluid build-up in lungs and limbs. Many people with heart failure, who tend to be older, have been found to be deficient in vitamin D.

“Heart failure will progress despite the best medications,” says Simpson, a professor of pharmacology at the U-M Medical School. “We think vitamin D retards that progression and protects the heart.”

The U-M researchers wanted to show whether a form of vitamin D could have beneficial effects on hearts that have developed or are at risk of developing heart failure. They used a breed of laboratory rats predisposed to develop human-like heart failure.

The researchers measured the effects of activated vitamin D (1,25 dihydroxyvitamin D3, a form called calcitriol) in rats given a normal diet or a high-salt diet, compared to control group rats given either of the same two diets, but no vitamin D treatment. The rats on the high-salt diet were likely to develop heart failure within months.

The rats on the high-salt diet, comparable to the fast food that many humans feast on, quickly revealed the difference vitamin D could make.

“From these animals, we have obtained exciting and very important results,” Simpson says.

After 13 weeks, the researchers found that the heart failure-prone rats on the high-salt diet that were given the calcitriol treatment had significantly lower levels of several key indicators of heart failure than the untreated high-salt diet rats in the study. The treated rats had lower heart weight. Also, the left ventricles of the treated rats’ hearts were smaller and their hearts worked less for each beat while blood pressure was maintained, indicating that their heart function did not deteriorate as it did in the untreated rats. Decreased heart weight, meaning that enlargement was not occurring, also showed up in the treated rats fed a normal diet, compared to their untreated counterparts.

Simpson and his colleagues have explored vitamin D’s effects on heart muscle and the cardiovascular system for more than 20 years. In 1987, when Simpson showed the link between vitamin D and heart health, the idea seemed far-fetched and research funding was scarce. Now, a number of studies worldwide attest to the vitamin D-heart health link.

The new heart insights add to the growing awareness that widespread vitamin D deficiency—thought to affect one-third to one-half of U.S. adults middle-aged and older—may be putting people at greater risk of many common diseases. Pharmaceutical companies are developing anti-cancer drugs using vitamin D analogs, which are synthetic compounds that produce vitamin D’s effects. There’s also increasing interest in using vitamin D or its analogs to treat autoimmune disorders.

In more than a dozen types of tissues and cells in the body, activated vitamin D acts as a powerful hormone, regulating expression of essential genes and rapidly activating already expressed enzymes and proteins. In the heart, Simpson’s team has revealed precisely how activated vitamin D connects with specific vitamin D receptors and produces its calming, protective effects. Those results appeared in the February issue of Endocrinology.

Sunlight causes the skin to make activated vitamin D. People also get vitamin D from certain foods and vitamin D supplements. Taking vitamin D supplements and for many people, getting sun exposure in safe ways, are certainly good options for people who want to keep their hearts healthy. But people with heart failure or at risk of heart failure will likely need a drug made of a compound or analog of vitamin D that will more powerfully produce vitamin D’s effects in the heart if they are to see improvement in their symptoms, Simpson says.

Vitamin D analogs already are on the market for some conditions. One present drawback of these compounds is that they tend to increase blood calcium to undesirable levels. Simpson’s lab is conducting studies of a specific analog which may be less toxic, so efforts to develop a vitamin D-based drug to treat heart failure are moving a step closer to initial trials in people.

Source: University of Michigan Health System

1,25-Dihydroxyvitamin-D3 Treatment Reduces Cardiac Hypertrophy and Left Ventricular Diameter in Spontaneously Hypertensive Heart Failure-Prone (cp/+) Rats Independent of Changes in Serum Leptin. Peter Mancuso, PhD; Ayesha Rahman, PhD; Stephen D Hershey, MD; Loredana Dandu, BS; Karl A Nibbelink, MD; Robert U Simpson, PhD. Journal of Cardiovascular Pharmacology. POST COPYEDIT, 15 May 2008. 10.1097/FJC.0b013e3181761906

Josh says:

I’ve always said that taking a multivitamin everyday has to increase your lifespan.

Moores UCSD Cancer Center study links vitamin D, type 1 diabetes

Sun exposure and vitamin D levels may play a strong role in risk of type 1 diabetes in children, according to new findings by researchers at the Moores Cancer Center at University of California, San Diego (UCSD) and the Department of Family and Preventive Medicine. This association comes on the heels of similar research findings by this same group regarding vitamin D levels and several major cancers.

In this new study, the researchers found that populations living at or near the equator, where there is abundant sunshine (and ultraviolet B irradiance) have low incidence rates of type 1 diabetes. Conversely, populations at higher latitudes, where available sunlight is scarcer, have higher incidence rates. These findings add new support to the concept of a role of vitamin D in reducing risk of this disease.

Ultraviolet B (UVB) exposure triggers photosynthesis of vitamin D3 in the skin. This form of vitamin D also is available through diet and supplements.

“This is the first study, to our knowledge, to show that higher serum levels of vitamin D are associated with reduced incidence rates of type 1 diabetes worldwide,” said Cedric F. Garland, Dr. P.H., professor of Family and Preventive Medicine in the UCSD School of Medicine, and member of the Moores UCSD Cancer Center.

The study is published June 5 in the online version of the scientific journal Diabetologia.

Type 1 diabetes is the second most common chronic disease in children, second only to asthma. Every day, 1.5 million Americans deal with type 1 diabetes and its complications. About 15,000 new cases are diagnosed in the United States each year, where this disease is the main cause of blindness in young and middle-aged adults and is among the top reasons for kidney failure and transplants in youth and midlife.

“This research suggests that childhood type 1 diabetes may be preventable with a modest intake of vitamin D3 (1000 IU/day) for children, ideally with 5 to 10 minutes of sunlight around noontime, when good weather allows,” said Garland. “Infants less than a year old should not be given more than 400 IU per day without consulting a doctor. Hats and dark glasses are a good idea to wear when in the sun at any age, and can be used if the child will tolerate them.”

The association of UVB irradiance to incidence of type 1 diabetes remained strong even after the researchers accounted for per capita healthcare expenditure. This was an important consideration because regions located near the equator tend to have lower per capita healthcare expenditures, which could result in under-reporting of type 1 diabetes.

The researchers created a graph with a vertical axis for diabetes incidence rates, and a horizontal axis for latitude. The latitudes range from -60 for the southern hemisphere, to zero for the equator, to +70 for the northern hemisphere. They then plotted incidence rates for 51 regions according to latitude. The resulting chart was a parabolic curve that looks like a smile.

In the paper the researchers call for public health action to address widespread vitamin D inadequacy in U.S. children.

“This study presents strong epidemiological evidence to suggest that we may be able to prevent new cases of type 1 diabetes,” said Garland. “By preventing this disease, we would prevent its many devastating consequences.”

Source: University of California – San Diego

Variants of vitamin D receptor linked to increased risk of breast cancer

Genetic variations in the body’s receptor for vitamin D could increase the risk of breast cancer in postmenopausal women, according to a study published today in the open access journal Breast Cancer Research.

Jenny Chang-Claude of the Division of Cancer Epidemiology, at the German Cancer Research Center, in Heidelberg, and colleagues there and at the Institute for Medical Biometrics and Epidemiology, University Clinic Hamburg-Eppendorf, Germany, undertook a population-based case-control study involving 1,408 patients and 2,612 control individuals. … Continue Reading »

Vitamin D and calcium influence cell death in the colon, researchers find

Researchers at Emory University are learning how vitamins and minerals in the diet can stimulate or prevent the appearance of colon cancer.

Emory investigators will present their findings on biological markers that could influence colon cancer risk in three abstracts at the American Association for Cancer Research meeting in San Diego.

In a clinical study of 92 patients, supplementing diet with calcium and vitamin D appeared to increase the levels of a protein called Bax that controls programmed cell death in the colon. More Bax might be pushing pre-cancerous cells into programmed cell death, says Emory researcher Veronika Fedirko, who will present her team’s results (abstract 464). … Continue Reading »