Vitamin (D) - Further Research

Vitamin D supplements could spare more than three million people from colds or flu in the UK each year, researchers claim.
The sunshine vitamin is vital for healthy bones, but also has a role in the immune system.
The analysis, published in the British Medical Journal, argues food should be fortified with the vitamin.

But Public Health England (PHE) says the infections data is not conclusive, although it does recommend supplements. These, it says, should be taken for improved bone and muscle health.  

The immune system uses vitamin D to make antimicrobial weapons that puncture holes in bacteria and viruses. But as vitamin D is made in the skin while out in the sun, many people have low levels during winter.

Trials on using supplements to prevent infections have given mixed results, so the researchers pooled data on 11,321 people from 25 separate trials to try to get a definitive answer.
The team at Queen Mary University of London (QMUL) looked at respiratory tract infections - which covers a wide range of illnesses from a sniffle to flu to pneumonia.

Overall, the study said one person would be spared infection for every 33 taking vitamin D supplements.
That is more effective than flu vaccination, which needs to treat 40 to prevent one case, although flu is far more serious than the common cold.
There were greater benefits for those taking pills daily or weekly - rather than in monthly super-doses - and in people who were deficient in the first place.

                           

               

Its main function is to regulate the amount of calcium and phosphate in the body, which are vital for the growth and maintenance of healthy bones, teeth and muscles.
In extreme cases, low levels can lead to rickets in children - where the bones become soft and weak and misshapen as they continue to grow.
In adults, vitamin D deficiency can lead to osteomalacia - causing severe bone pain and muscle aches. But there is a balance - too much vitamin D can lead to high levels of calcium in the blood which can cause heart and kidney problems.
Anyone with a chronic condition or taking medication should seek advice from their doctor.

One of the researchers, Prof Adrian Martineau, said: "Assuming a UK population of 65 million, and that 70% have at least one acute respiratory infection each year, then daily or weekly vitamin D supplements will mean 3.25 million fewer people would get at least one acute respiratory infection a year."
PHE already advises everyone to take vitamin D supplements in autumn and winter for the sake of healthy bones and muscles.
They are recommended all year round for some people who get little sunlight on their skin, including people in care homes or those who cover up.

However, there is considerable debate about the importance of the latest study.
Prof Louis Levy, the head of nutrition science at PHE, said: "The evidence on vitamin D and infection is inconsistent and this study does not provide sufficient evidence to support recommending vitamin D for reducing the risk of respiratory tract infections."
But Prof Martin Hewison, from the University of Birmingham and the Society for Endocrinology, said the findings were "striking".
"I agree with the authors that this study supports a new indication for vitamin D beyond its established benefits for bone health," he added.
And the research wing of the NHS, the National Institute for Health Research which funded the study, said the findings were "worthy of serious further debate".
Ultimately, the researcher team at QMUL want vitamin D to be added to food like in the US where milk is fortified.
Prof Martineau said: "Vitamin D fortification of foods provides a steady, low-level intake of vitamin D that has virtually eliminated profound vitamin D deficiency in several countries.
"By demonstrating this new benefit of vitamin D, our study strengthens the case for introducing food fortification to improve vitamin D levels in countries such as the UK where profound vitamin D deficiency is common."

Vitamin (D) Levels - Dublin Area

Almost 13% of the population of greater Dublin is deficient in Vitamin D, according to a new study by researchers at Trinity College Dublin and St James' Hospital.

Researchers have visually mapped, for the first time, the Vitamin D status of the capital's inhabitants.
The visualisation shows great variation in the levels of deficiency across the city, with noticeable differences in particular areas.
Vitamin D can be provided by UV-B radiation from the sun, as well as certain foods and supplements.

Deficiency is associated with musculoskeletal and bone health conditions such as rheumatoid arthritis and osteoporosis, and may also be a risk factor in other conditions such as heart disease, type-2 diabetes, cancer and inflammatory conditions.
The most social economically deprived and ethnically diverse urban locations, as well as Dublin 8 and Lucan, had deficiency rates of 25% - the highest across the region and double the average rate for the Dublin area as a whole.
Dublin 16 during the summer months had the lowest rates of deficiency at 5%, while during the winter the lowest rate was found in Kildare at 7.6%.

                       

Winter Months:
Those aged between 18 and 50 had lower levels of the vitamin in their bodies than those aged over 50 during both summer and winter.
"Other studies have shown an association between social deprivation and lower vitamin D, possibly due to diet as vitamin D-rich foods, such as oily fish or fortified foods, tend to be more expensive," said Dr Eamon Laird, author of the study and Research Fellow at the Centre for Medical Gerontology at TCD.
"Also, these locations in Dublin are more ethnically diverse compared to other areas, with higher numbers of non-Caucasians.
"Increased skin pigmentation plus ethnic lifestyle choices such as traditional clothing and/or dietary habits can also increase the risk of deficiency."
Overall the deficiency rate across the greater Dublin areas is, however, similar to that found in a large recent study of European adults.
Those behind the research say such studies can help with the identification of those most at risk, which can help with the formulation of public health policy.
The publication of the research coincides with international Vitamin D awareness day, today 2 November.
The study involved carrying out traditional research on 5,200 individuals, and combining that with geo-mapping techniques.

Vitamin D levels impact mobility in severely obese

New HRB-funded research shows that severely obese people with low vitamin D levels walk slower and are less active than their counterparts who have healthy vitamin D levels.

The study, led by Dr Tomás Ahern from St. Columcille’s Hospital and St. Vincent’s University Hospital, examined physical functioning and vitamin D levels in 252 severely obese people.

Participants were timed as they walked 500 meters and climbed up and down a single step 50 times. They also provided estimates of their physical activity. 

Researchers took a blood sample to measure each participant’s vitamin D levels.

The study found the group with the highest vitamin D levels had the fastest walking times and highest amount of self-reported physical activity. This group also had the lowest average Body Mass Index (BMI) of the study participants.

'Increasing vitamin D status should improve quality of life and may decrease the risk of early death severely obese people', Ahern says. 'This could be a simple matter of spending more time outside, since sun exposure can boost the body’s natural vitamin D production'.

Graham Love, Chief Executive of the HRB, says,

‘Research has most impact if the findings are put into practice. This study shows that a simple change in people’s behaviour could have a positive effect on their health.  The Health Research Board is committed to investing in research that delivers good evidence for decision-making in relation to health, whether it is at an individual, clinical or national level’.

View press release here