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Increased B vitamins may ease PMS

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Higher intakes of the B vitamins thiamine and riboflavin from the diet may reduce the incidence of premenstrual syndrome (PMS) by about 35 percent, suggest new findings. According to a new paper published in the American Journal of Clinical Nutrition, the link between B vitamins and PMS is biologically plausible since B vitamins such as thiamine and riboflavin are known to play important roles in the synthesis of various neurotransmitters involved in PMS.

While most women experience mild emotional or physical premenstrual symptoms, as many as 8-20 per cent of women experience symptoms severe enough to meet the definition of premenstrual syndrome, which can substantially interfere with daily activities and relationships. The new study, performed by researchers from the University of Massachusetts, Harvard, and the University of Iowa, indicates that increase intakes of certain B vitamins from food sources may help reduce the incidence of PMS.

Using data from 1,057 women with PMS and 1,968 women without PMS participating in the Nurses' Health Study II cohort, the researchers found that women with the highest average intakes of riboflavin two to four years prior to diagnosis were associated with a 35 percent lower incidence of PMS than women with the lowest average intakes. On the other hand, the researchers did not observe any benefits with other B vitamins, including niacin, folate, B6, and B12. In addition, supplemental intakes of these vitamins was not linked to PMS incidence, they added. “We observed a significantly lower risk of PMS in women with high intakes of thiamine and riboflavin from food sources only,” wrote the researchers. “Further research is needed to evaluate the effects of B vitamins in the development of premenstrual syndrome.”

Beyond the B vitamins, there is also some evidence for the potential of a diet rich in calcium and vitamin D to lower the risk of developing PMS, a condition that affects up to a fifth of all women. According to a study published in 2005 in the Archives of Internal Medicine (Vol. 165, pp1246-1252), researchers from the University of Massachusetts and GlaxoSmithKline reported for the first time that calcium and vitamin D may help prevent the initial development of PMS.

Source: The American Journal of Clinical Nutrition. Published online ahead of print, doi: 10.3945/ajcn.110.009530 “Dietary B vitamin intake and incident premenstrual syndrome” Authors: P.O. Chocano-Bedoya, J.E. Manson, S.E. Hankinson, W.C. Willett, S.R. Johnson, L. Chasan-Taber, A.G. Ronnenberg, C. Bigelow, E.R. Bertone-Johnson

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Obesity leads to Vitamin D deficiency

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People who weigh more have lower circulating levels of Vitamin D according to recent research conducted at the Rikshospitalet-Radiumhospitalet Medical Center in Oslo, Norway and published in the Journal of Nutrition. Lead researcher, Zoya Lagunova, MD and her colleagues measured the serum levels of Vitamin D and 1,25(OH)2D in 1,779 patients at a Medical and Metabolic Lifestyle Management Clinic in Oslo, Norway. The associations among 1,25(OH)(2)D, serum 25-hydroxyvitamin D [25(OH)D], and body composition were analyzed. Lagunova noted that generally people with higher BMI had lower levels of Vitamin D. Age, season, and gender were also found to influence serum 1,25(OH)(2)D.

Vitamin D is not a true vitamin, but rather a vitamin-steroid thought to play a key role in the prevention of cancer, cardiovascular disease, diabetes, multiple sclerosis and other diseases. It is likely not coincidental that obesity is also a risk factor for many of these diseases. Vitamin D is vital to the regulation of calcium. Studies have shown that calcium deficiency increases the production of synthase, an enzyme that converts calories into fat. It has been shown that calcium deficiency can increase synthase production by up to 500 percent. Vitamin D has also been shown to play a role in the regulation of blood sugar levels; proper blood sugar regulation is vital to the maintenance of a healthy weight. Vitamin D is produced from sunlight and converted into various metabolites. It is stored in fat tissue. According to Lagunova, obese people may take in as much Vitamin D as other people; however, because it is stored in fat it may be less available. This may result in lower circulating levels of Vitamin D.

A previous study conducted by Shalamar Sibley, MD, MPH, an assistant professor of medicine at the University of Minnesota, showed that subjects who have higher levels of Vitamin D at the start of a weight loss diet lose more weight than those with lower levels. The study measured Vitamin D levels of 38 overweight men and women both before and after following an 11-week calorie-restricted diet. Vitamin D levels at the start of diet was an accurate predictor of weight loss…those with higher levels of Vitamin D lost more weight. It was found that for every nanogram increase in Vitamin D precursor, there was an 1/2 pound increase in weight loss.

Seventy-five percent or more of Americans, teenage and older, are Vitamin D deficient according to a recent study published in the Archives of Internal Medicine. According to the Gallup-Healthways Well-Being Index, 26.5% of American are obese. More research needs to be conducted into the exact role Vitamin D plays in obesity and weight loss and the possibility of increased Vitamin D consumption (through the form of supplementation and/or increased sun exposure) being a key factor to achieving a healthy weight.

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Obesity may interfere with Vitamin D absorption

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The more obese a person is, the poorer his or her vitamin D status, a new study by a team of Norwegian researchers suggests. The study found an inverse relationship between excess pounds and an insufficient amount of vitamin D, which is critical to cell health, calcium absorption and proper immune function. Vitamin D deficiency can raise the risk for bone deterioration and certain types of cancer. The researchers also suggest that overweight and obese people may have problems processing the vitamin properly.

The team noted that after the so-called “sunshine vitamin” is initially absorbed (through either sun exposure or the consumption of such foods as oily fish and fortified milk), the body must then convert it into a usable form, called 1,25-dihydroxyvitamin D. This conversion process, however, seems to be short-circuited among obese people, complicating efforts to gauge their true vitamin D health.

The findings are published in the January issue of the Journal of Nutrition.

To investigate the impact of obesity on vitamin D absorption, the team spent six years tracking 1,464 women and 315 men, with an average age of 49. Based on the participants' body mass index (BMI), an indicator of body fatness calculated from a persons weight and height, the average participant was deemed to be obese. About 11 percent were categorized as “morbidly obese.”

From the outset, overall vitamin D levels were found to be below the healthy range, the authors noted. By the end of the study, overall levels of vitamin D were found to have dropped off “significantly” while BMI readings rose by 5 percent. The research team concluded that having a higher-than-normal weight, body fat and BMI was linked to a poorer vitamin D profile. For example, people with the lowest BMI readings had 14 percent higher vitamin D levels than those with the highest BMI readings. Because vitamin D levels did not correlate properly with 1,25-dihydroxyvitamin D levels (and in fact appeared to have an abnormal inverse relationship), the authors suggested that future efforts to explore vitamin D status among obese people should test for both measures of vitamin D health.

They also suggested that people who are overweight and obese might benefit from vitamin D supplementation and more exposure to sunlight.

SOURCE: Journal of Nutrition, news release, Dec. 14, 2010

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Obesity may interfere with Vitamin D absorption

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The more obese a person is, the poorer his or her vitamin D status, a new study by a team of Norwegian researchers suggests. The study found an inverse relationship between excess pounds and an insufficient amount of vitamin D, which is critical to cell health, calcium absorption and proper immune function. Vitamin D deficiency can raise the risk for bone deterioration and certain types of cancer.

The researchers also suggest that overweight and obese people may have problems processing the vitamin properly.

The team noted that after the so-called “sunshine vitamin” is initially absorbed (through either sun exposure or the consumption of such foods as oily fish and fortified milk), the body must then convert it into a usable form, called 1,25-dihydroxyvitamin D. This conversion process, however, seems to be short-circuited among obese people, complicating efforts to gauge their true vitamin D health.

The findings are published in the January issue of the Journal of Nutrition.

To investigate the impact of obesity on vitamin D absorption, the team spent six years tracking 1,464 women and 315 men, with an average age of 49. Based on the participants' body mass index (BMI), an indicator of body fatness calculated from a persons weight and height, the average participant was deemed to be obese. About 11 percent were categorized as “morbidly obese.”

From the outset, overall vitamin D levels were found to be below the healthy range, the authors noted. By the end of the study, overall levels of vitamin D were found to have dropped off “significantly” while BMI readings rose by 5 percent.

The research team concluded that having a higher-than-normal weight, body fat and BMI was linked to a poorer vitamin D profile. For example, people with the lowest BMI readings had 14 percent higher vitamin D levels than those with the highest BMI readings. Because vitamin D levels did not correlate properly with 1,25-dihydroxyvitamin D levels (and in fact appeared to have an abnormal inverse relationship), the authors suggested that future efforts to explore vitamin D status among obese people should test for both measures of vitamin D health.

They also suggested that people who are overweight and obese might benefit from vitamin D supplementation and more exposure to sunlight.

SOURCE: Journal of Nutrition, news release, Dec. 14, 2010

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Vitamin D affects more than 200 genes

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Working in the laboratory, the scientists isolated fragments of DNA in cells to study the effects of exposure to calcitriol, the “active” form of vitamin D. Their findings are published in the journal Genome Research.

Vitamin D influences DNA through a “go-between” protein called the vitamin D receptor (VDR). The protein is activated by the vitamin and attaches itself to DNA at the binding sites the researchers identified. VDR binding was enriched in disease-associated regions of the genetic code and also areas linked to traits such as tanning, height and hair colour.

Study leader Dr Sreeram Ramagopalan, from the Wellcome Trust Centre for Human Genetics, at Oxford University, said: “There is now evidence supporting a role for vitamin D in susceptibility to a host of diseases. Vitamin D supplements during pregnancy and the early years could have a beneficial effect on a child's health in later life. “Some countries, such as France, have instituted this as a routine public health measure.”

Vitamin D is chiefly made in the body as a result of the skin's exposure to sunlight. A small number of foods also contain the vitamin, including oily fish and eggs, but 90% comes from being in the sun. In many northern countries, a lack of sun can lead to vitamin D deficiency. Over-zealous use of sunscreen can also prevent vitamin D production. It is estimated that more than half the UK population do not get enough vitamin D, and worldwide a billion people may be deficient in the vitamin. Lack of vitamin D affects bone growth and development, leading to rickets in children and bone fractures in adults.

The study supports the theory that lighter, more sun-sensitive skins evolved as people migrated north out of Africa to maximise vitamin D production in the body. A significant number of the VDR binding sites were in DNA regions where genetic changes are commonly found in people of European and Asian descent.

“Vitamin D status is potentially one of the most powerful selective pressures on the genome in relatively recent times,” said co-author Professor George Ebers, also from the Wellcome Trust Centre for Human Genetics. “Our study appears to support this interpretation and it may be we have not had enough time to make all the adaptations we have needed to cope with our northern circumstances.”

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Vitamin D Might Fight Colds

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“However,” the researcher said, “there is a lack of clinical studies of the effect of vitamin D supplementation for preventing respiratory infections.”

For the current study, Laaksi's team randomly assigned 164 male military recruits to take either 400 international units (IU) of vitamin D or inactive placebo pills every day for six months — from October to March, covering the months when people's vitamin D stores typically decline and when respiratory infections typically peak.

At the end of the study, the researchers found no clear difference between the two groups in the average number of days missed from duty due to a respiratory infection — which included bronchitis, sinus infections, pneumonia, ear infections and sore throat.

On average, men who took vitamin D missed about two days from duty because of a respiratory infection, compared with three days in the placebo group. That difference was not significant in statistical terms.

However, men in the vitamin D group were more likely to have no days missed from work due to a respiratory illness.

Overall, 51 percent remained “healthy” throughout the six-month study, versus 36 percent of the placebo group, the researchers report.

The findings, Laaksi said, offer “some evidence” of a benefit from vitamin D against respiratory infections.

Still, the extent of the benefit was not clear. While recruits in the vitamin group were more likely to have no days missed from duty, they were no less likely to report having cold-like symptoms at some point during the study period.

Moreover, recent studies on the usefulness of vitamin D for warding off respiratory ills have come to conflicting conclusions.

A study of Japanese schoolchildren published earlier this year found that those given 1,200 IU of vitamin D each day during cold and flu season were less likely to contract influenza A. Of 167 children given the supplement, 18 developed the flu, compared with 31 of 167 children given placebo pills.

On the other hand, a recent study of 162 adults found that those who took 2,000 IU of vitamin D everyday for 12 weeks were no less likely to develop respiratory infections than those given placebo pills.

Laaksi said that larger clinical trials looking at different doses of vitamin D are still needed before the vitamin can be recommended for curbing the risk of respiratory infections.

In the U.S., health officials recommend that adults up to the age of 50 get 200 IU of vitamin D each day, while older adults should get 400 to 600 IU. The upper limit is currently set at 2,000 IU per day; higher intakes may raise the risks of side effects.

Symptoms of vitamin D toxicity are often vague and include nausea, vomiting, constipation, poor appetite and weight loss. Excessive vitamin D in the blood can also raise blood pressure or trigger heart rhythm abnormalities.

Some researchers believe that people need more vitamin D than is currently recommended, and that intakes above 2,000 IU per day are safe. However, exactly what the optimal vitamin D intake might be remains under debate.

Food sources of vitamin D include milk, breakfast cereals and orange juice fortified with vitamin D, as well as some fatty fish, like salmon and mackerel. Experts generally recommend vitamin pills for people who do not get enough of the vitamin from food.

SOURCE: Journal of Infectious Diseases

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12 Ways Vitamin D Can Help

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Vitamin D, the “sunshine” vitamin, does a lot more than help keep bones strong — scientists are finding that it impacts all aspects of our health.

Vitamin D can be obtained from exposure to sunlight, vitamin supplements (vitamin D-3 is recommended by many experts), and foods such as salmon and tuna.

Recent studies show that having high levels of vitamin D in our blood can help protect against many diseases, while low levels are linked with several disorders.

Here are 12 critically important ways vitamin D can help protect your health:

1. Colon cancer. A study by cancer prevention specialists at the Moores Cancer Center at the University of California found that high amounts of vitamin D could slash colorectal cancer rates by two-thirds. A European study found that high levels of vitamin D cut the odds of colon cancer by almost 40 percent.

2. Breast cancer. Research using data from two earlier studies found that women with the highest amounts of vitamin D in their blood lowered their risk of breast cancer by 50 percent when compared to women with the lowest levels. A Canadian study found that women who took a vitamin D pill of least 400 international units every day lowered their risk of developing breast cancer by 24 percent.

3. Heart disease. A British study has found that middle-aged and elderly people with high levels of vitamin D reduce their risk of developing cardiovascular disease by 33 percent. Utah scientists found that patients who raised their blood levels of vitamin D after being diagnosed as deficient lowered their risk of having a heart attack by 33 percent, their risk of heart failure by 20 percent, and their risk of dying from any cause by 30 percent.

4. Brain health. A European study of men between the ages of 40 and 79 found that high levels of vitamin D were associated with high scores on memory tests.

5. Diabetes. Researchers at Warwick Medical School found that adults with the highest blood levels of vitamin D lowered their risk of developing Type 2 diabetes by 55 percent.

6. Asthma. Asthmatics who have high levels of vitamin D have better lung function and respond to treatment better than those who have low levels, according to researchers at National Jewish Health in Denver.

7. Bone health. Vitamin D and calcium reduce the risk of hip fractures in the elderly. Studies show that people who are deficient in vitamin D absorb 65 percent less calcium than those with normal levels. One recent study from the United Kingdom found that 95 percent of patients with hip fractures were deficient in vitamin D, and having adequate levels could reduce hip fractures by up to 50 percent.

8. Depression. University of Toronto researchers found that people who suffer from depression, especially those with seasonal affective disorder, improved as the levels of vitamin D in the blood rose. Researchers in Norway found that high doses of vitamin D helped relieve the symptoms of depression.

9. Multiple sclerosis. Australian scientists discovered that people who live in the state furthest from the equator — and get less sunlight — are seven times more likely to develop multiple sclerosis than those who live in the sunniest state.

10. Colds and flu. Scientists at the University of Colorado found that people with the lowest amounts of vitamin D in their blood had the highest incidence of colds and flu.

11. Rheumatoid arthritis. Researchers from the University of Alabama, Birmingham, found that women with the highest levels of vitamin D in their blood lowered their chances of developing rheumatoid arthritis by 30 percent.

12. Crohn's Disease. Vitamin D switches on genes responsible for fighting Crohn's disease (a chronic inflammatory disease primarily affecting the small and large intestine), according to Canadian researchers. “Our data suggests that vitamin D deficiency can contribute to Crohn's disease,” Dr. John White, endocrinologist at the Research Institute of the McGill University Health Center in Montreal, Canada, said in a statement.

(Source: National Institute of Health UK)

 

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Vitamin K tied to lower cancer risk

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In the current study, vitamin K2 — which study participants most frequently got through cheese — was linked to the odds of developing or dying from cancer, whereas vitamin K1 was not.

The findings are based on data from 24,340 German adults who were between the ages of 35 and 64, and cancer-free at the outset. The researchers estimated the participants' usual vitamin K intake based on a detailed dietary questionnaire. Over the next decade, 1,755 participants were diagnosed with colon, breast, prostate or lung cancers, of whom 458 died during the study period.

In general, the researchers found, the one quarter with the highest intakes of vitamin K2 were 28 percent less likely to have died of any one of the cancers than the one-quarter of men and women with the lowest intakes of the vitamin. That was with factors like age, weight, exercise habits, smoking and consumption of certain other nutrients, like fiber and calcium, taken into account.

Of the one-quarter of study participants who got the least vitamin K2, 156 — or 2.6 percent — died of one of the four cancers. That was true of 1.6 percent of participants with the highest intakes of the vitamin from food.

When Linseisin's team looked at the cancer types individually, there was no clear link between either form of vitamin K and breast cancer or colon cancer. However, greater consumption of vitamin K2 was linked to lower risks of developing or dying from lung cancer — a disease for which smoking is the major risk factor — or of developing prostate cancer.

Of the one-quarter of study participants with the lowest vitamin K2 intakes, 47 — or 0.8 percent — developed lung cancer, versus 0.4 percent of the one-quarter who got the most vitamin K2 in their diets. When it came to prostate cancer, there were 111 cases among the one-quarter of men with the lowest vitamin K2 intakes, and 65 cases in the group with the highest consumption.

In theory, vitamin K itself could offer some protection against cancer. It's often used to counteract too-high doses of blood thinners, although this does not have an obvious link to cancer. In lab research, however, Linseisin and his colleagues point out, the vitamin has been shown to inhibit cancer cell growth and promote apoptosis — a process by which abnormal cells kill themselves off.

But whether vitamin K intake itself is responsible for the lower cancer risks in this study is unclear, according to the researchers. One limitation is that they estimated vitamin K intake based on participants' reported eating habits; most of their vitamin K came from eating cheese, and it's possible, Linseisin and his colleagues note, that some other components of that food are related to cancer risk.

Future studies, the researchers say, should measure people's blood levels of vitamin K and look at the relationship of those levels with cancer risks.

SOURCE: American Journal of Clinical Nutrition

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Vitamin D – What you need to know

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Some people may be at risk of not getting enough vitamin D because they don’t get enough in their diet or because they have more limited sun exposure which reduces the amount of vitamin D their bodies make. Those at risk include:

  • Breastfed infants require 400 IU vitamin D per day from birth. Because breast milk is naturally low in vitamin D and infants are not usually exposed to the sun, a vitamin D supplement of 400 IU is recommended. Healthy term infants fed infant formula do not require a vitamin D supplement as it is already added to the formula.
  • Pregnant women should consume vitamin D from food (for example, from a least 3 glasses of milk der day) or supplements (usually 200-400 IU is provided in a supplement) to ensure the baby is born with optimal vitamin D in their body. If a supplement is taken, be sure not to exceed 2000 IU vitamin D per day.
  • Adults over 50 years may not prodce vitamin D in skin as well as when they were younger. It is recommended that adults (men and women) over 50 years take a supplement of 400 IU / day.
  • People with skin darkly pigmented with melanin are less able to make vitamin D from exposure to sunlight. Since many people with darker skin colour also avoid vitamin D fortified milk due to lactose intolerance, their dietary intake of the vitamin may be low, so extra vitamin D, such as the amount typically found in a general multivitamin-mineral supplement (200-400 IU) would be a good idea.
  • People with limited sun exposure sun exposure is limited due to mostly living or working indoors, wearing clothing such as long robes and head coverings, then it is wise to carefully choose vitamin D rich foods (see above) or to take a vitamin D supplement, such as the amount typically found in a general multivitamin-mineral supplement (200-400 IU).
  • Some medical conditions such as Crohn's disease, cystic fibrosis, celiac disease, surgical removal of part of the stomach or intestines, and some forms of liver disease, interfere with absorption of vitamin D. Being overweight and obese causes fat to stay stored in fat tissues and not be released into the blood, preventing vitamin D from being available to the body. If you have one of these conditions, check with your doctor to ask if a vitamin D supplement is needed.
  • Can I take too much vitamin D?

    Yes. Too much vitamin D can be harmful. The total daily intake from food and supplements combined should not exceed 1000 IU for infants and young children and 2000 IU for adults.

    The Bottom Line

    Most people, except those in the risk groups noted above, can get enough vitamin D if they eat enough vitamin D rich foods (for example, milk, vitamin D fortified foods and some fatty fish) and if they engage in safe sun practices. If you are concerned about your vitamin D status, discuss the issue with Nastaran.

    Source: Dietitians of Canada. Reproduced with Permission. Note: The Australian adequate intake is 200 IU however Nastaran recommends 400 IU as per the Canadian recommended intake.

     

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