Antioxidant vitamins may raise death risk

Now even vitamins are bad for ya...

Feb 28, 2007 - Antioxidant vitamins may not always as good as intended, according to some researchers.

A new meta-analysis of 68 randomized trials with 232 606 participants suggests that treatment with beta carotene, vitamin A, and vitamin E may increase risk of death whereas the effect of vitamin c and selenium on the death risk remains unclear. The study published in the Feb. 28, 2007 issue of the Journal of the American Medical Association has drawn immediate criticism from the Council of Responsible Nutrition which issued a statement suggesting that the analysis is inadequate because the studies used in the analysis differ greatly in terms of their designs, size and quality.

The trade organization representing vitamin supplements manufacturers says in its press release that the researchers “misuse meta-analysis methods to create generalized conclusions that may inappropriately confuse and alarm consumers who can benefit from supplementing with antioxidants." The antioxidant vitamins of concern are often times marketed as dietary supplements and used by consumers in hopes to maintain their health or protect against diseases such as cancer and heart disease as these compounds can presumably help eliminate free radials (at least in a theoretical sense) that would otherwise injure cells, leading to cancer, premature aging and other illnesses. But early studies are inconsistent in terms of the effects of these noted antioxidant vitamins.

In the current study, Dr Goran Bjelakovic, from Copenhagen University Hospital, Denmark and colleagues conducted a comprehensive review on more than 300 trail articles published by October 2005 and meta-analyzed data derived form these publications to examine if these vitamins indeed have any effect on mortality resulting from all causes. For the study, the researchers selected certain publications/trials based on certain criteria with regard to its quality and reliability. When 68 were selected from 815 trials, they came to find that the results were inconclusive. And use of the vitamins was not associated with elevated risk of death. A further reduction of trials by 21 led to results indicating that vitamins were linked with an elevated risk of death.

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Guess vitamin D is safe...

Vitamin D increases life expectancy, study finds
Mon. Sep. 10 2007 - An intriguing new study finds that those who take vitamin D supplements can increase their life expectancies by one to two years.

The study, published in the Archives of Internal Medicine, is just the latest to add to the growing body of evidence that "the sunshine vitamin" is not just good for strengthening bones but also appears to increase survival.

Past studies have suggested that vitamin D deficiencies might be associated with a higher risk of death from cancer, heart disease and diabetes -- illnesses that account for 60 to 70 per cent of deaths in high-income nations. This study finds that taking extra vitamin D brings health benefits, even in the short term. This study looked at the results of 18 previously published studies involving a total of 57,311 participants.

Dr. Philippe Autier, of the International Agency for Research on Cancer, Lyon, France, and Sara Gandini, of the European Institute of Oncology, Milano, Italy, analyzed the studies and evaluated doses of vitamin D ranging from 300 to 2,000 international units, with an average dose of 528 international units.

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Vitamin D affects pain threshold in women...

Pain 'linked with low vitamin D'
Monday, 11 August 2008 - Low vitamin D levels may contribute to chronic pain among women, say scientists.

Low levels of the sunshine vitamin, vitamin D, may contribute to chronic pain among women, scientists believe. The link does not apply to men, suggesting hormones may be involved, according to a study published in the Annals of Rheumatic Diseases said. The team from the Institute of Child Health in London said studies were now needed to see if vitamin D supplements can guard against chronic pain.

About one in 10 people are affected by chronic pain at any one time in the UK. The causes are not well understood and much of the focus to date has been on emotional factors. Dr Elina Hyppönen and colleagues believe, at least in women, vitamin D levels could play a role in some cases of chronic pain.

Sunshine vitamin

The nutrient, essential for healthy bones, is produced in the body when exposed to sunlight and is also found in oily fish, egg yolks and margarine. Among the 7,000 men and women aged 45 from across England, Scotland and Wales that they studied, those who were smokers, non-drinkers, the overweight and the underweight all reported higher rates of chronic pain.

Among the women, vitamin D levels also appeared to be important. This finding was not explained by gender differences in lifestyle or social factors, such as levels of physical activity and time spent outdoors, say the authors.

More BBC NEWS | Health | Pain 'linked with low vitamin D'

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Lower B12 levels linked to brain shrinkage...

Vitamin linked to brain shrinking
Monday, 8 September 2008 - A vitamin found in meat, fish and milk may help stave off memory loss in old age, a study has suggested.

Older people with lower than average vitamin B12 levels were more than six times more likely to experience brain shrinkage, researchers concluded. The University of Oxford study, published in the journal Neurology, tested the 107 apparently healthy volunteers over a five-year period. Some studies suggest two out of five people are deficient in the vitamin. "The rate of shrinkage of the brain as we age may be partly influenced by what we eat" - Professor David Smith, Oxford University

The problem is even more common among the elderly, and recent moves to supplement bread with folic acid caused concern that this could mask B12 deficiency symptoms in older people. The Oxford study looked at a group of people between 61 and 87, splitting it into thirds depending on the participants' vitamin B12 levels. Even the third with the lowest levels were still above a threshold used by some scientists to define vitamin B12 deficiency. However, they were still much more likely to show signs of brain shrinkage over the five-year period.

Liver and shellfish

Professor David Smith, who directs the Oxford Project to Investigate Memory and Ageing, said he now planned a trial of B vitamins in the elderly to see if taking them could slow brain shrinkage. He said: "This study adds another dimension to our understanding of the effects of B vitamins on the brain - the rate of shrinkage of the brain as we age may be partly influenced by what we eat." Shrinkage has been strongly linked with a higher risk of developing dementia at a later stage and Rebecca Wood, the chief executive of the Alzheimer's Research Trust, said further research was needed. "This study suggests that consuming more vitamin B12 through eating meat, fish, fortified cereals or milk as part of a balanced diet might help protect the brain. Liver and shellfish are particularly rich sources of B12.

"Vitamin B12 deficiency is a common problem among elderly people in the UK and has been linked to declining memory and dementia." Dr Susanne Sorensen, from the Alzheimer's Society said: "Shrinkage is usually associated with the development of dementia. "As vitamin B may be given as a food supplement, it may be useful to include tests of vitamin B levels in the general assessment of health of older individuals. "This is another example of why it is crucial for people to lead a healthy lifestyle with a balanced diet rich in B vitamins and antioxidants. "The best way to reduce your risk of developing dementia is to keep active, eat a balanced diet, don't smoke and visit your GP to get your blood pressure and cholesterol checked."

BBC NEWS | Health | Vitamin linked to brain shrinking