Everyone loves D, the sunshine vitamin. Doctors, patients and the media have been enamoured with vitamin D supplements for decades. As well as their clear benefit in curing severe vitamin D deficiencies, endless headlines hail their magical ability to reduce a vast range of conditions from dementia to cancer.
Medical specialists such as myself have been promoting supplements to our patients with osteoporosis and other bone problems for decades. Many food products contain artificially added vitamin D with the aim of preventing fractures and falls and improving muscle strength although the vitamin also has been claimed to boost the immune system and reduce ageing. I used to sometimes take vitamin D myself and recommended it to my family to survive sun-starved winters.
However, a new paper on the risks that vitamin D may pose finally has convinced me that I was wrong. My view on vitamin supplements and the multi-billion dollar industry behind them altered radically after I began researching my book, The Diet Myth, in 2013. The industry and its PR is supported by celebrities who reportedly have high-dose vitamins drip fed into their veins, and around 50% of Americans and Britons take them regularly. But surprisingly, there is a lack of evidence to support the health benefit claims of virtually all vitamin supplements on the market.
One study based on the large SELECT trial suggested that supplements such as vitamin E and selenium actually increased prostate cancer in some men. And last year massive analyses combining 27 studies on half a million people concluded that taking vitamin and mineral supplements regularly failed to prevent cancer or heart disease. Not only are they a waste of money for the majority of us – but if taken in excessive quantities they can actually hasten an early death, increasing your risk of heart disease and cancer.
Virtually no vitamins or supplements have actually been shown to have any benefit in proper randomised trials in normal people without severe deficiencies. Rare exceptions have been lutein nutrients for macular degeneration, a common cause of blindness – and vitamin D, the golden boy of vitamins.
Since the 1980s, researchers (including myself) have written thousands of papers, associating a lack of our favourite vitamin with over 137 diseases. A 2014 BMJ report, however, found these links mainly to be spurious.
Won’t do you any harm?
Our genetic makeup influences vitamin D levels. We can use this information to tell if naturally low vitamin D levels might actually increase the risk of disease (rather than be a consequence of it). The evidence so far suggests (with the possible exception of multiple sclerosis and some cancers) that low vitamin D levels are either irrelevant or merely a marker of the disease.
Until now we haven’t worried about giving people extra vitamin D because we thought “it might help anyway and of course (as it’s a vitamin) doesn’t do you any harm”. With our increasing knowledge, we should now know better. Recent studies in the last five years have suggested that even calcium supplements as well as being ineffective in preventing fracture can increase the risk of heart disease.
While several studies in normal people failed to find any protective effects from vitamin D, others have been more worrying. One 2015 randomised study of 409 elderly people in Finland suggested that vitamin D failed to offer any benefits compared to placebo or exercise – and that fracture rates were, in fact, slightly higher.
The usual prescribed dose in most countries is 800 to 1,000 units per day (so 24,000-30,000 units per month). However, two randomised trials found that at around 40,000 to 60,000 units per month Vitamin D effectively became a dangerous substance.
One study involving over 2,000 elderly Australians, which was largely ignored at the time, and the one just published found that patients given high doses of vitamin D or those on lower doses that increased vitamin D blood levels within the optimal range (as defined by bone specialists) had a 20-30% increased rate of fractures and falls compared to those on low doses or who failed to reach “optimal blood levels”.
Health news in pictures
Health news in pictures
1/25 Most child antidepressants are ineffective and can lead to suicidal thoughts
The majority of antidepressants are ineffective and may be unsafe, for children and teenager with major depression, experts have warned. In what is the most comprehensive comparison of 14 commonly prescribed antidepressant drugs to date, researchers found that only one brand was more effective at relieving symptoms of depression than a placebo. Another popular drug, venlafaxine, was shown increase the risk users engaging in suicidal thoughts and attempts at suicide
2/25 'Universal cancer vaccine’ breakthrough claimed by experts
Scientists have taken a “very positive step” towards creating a universal vaccine against cancer that makes the body’s immune system attack tumours as if they were a virus, experts have said. Writing in Nature, an international team of researchers described how they had taken pieces of cancer’s genetic RNA code, put them into tiny nanoparticles of fat and then injected the mixture into the bloodstreams of three patients in the advanced stages of the disease. The patients' immune systems responded by producing "killer" T-cells designed to attack cancer. The vaccine was also found to be effective in fighting “aggressively growing” tumours in mice, according to researchers, who were led by Professor Ugur Sahin from Johannes Gutenberg University in Germany
3/25 Green tea could be used to treat brain issues caused by Down’s Syndrome
A compound found in green tea could improve the cognitive abilities of those with Down’s syndrome, a team of scientists has discovered. Researchers found epigallocatechin gallate – which is especially present in green tea but can also be found in white and black teas – combined with cognitive stimulation, improved visual memory and led to more adaptive behaviour. Dr Rafael de la Torre, who led the year-long clinical trial along with Dr Mara Dierrssen, said: “The results suggest that individuals who received treatment with the green tea compound, together with the cognitive stimulation protocol, had better scores in their cognitive capacities”
4/25 New online test predicts skin cancer risk
Health experts have created a new online tool which can predict a person’s risk of developing a common form of skin cancer. The tool uses the results of a 10-question-quiz to estimate the chance of a person aged 40 or over of having non-melanoma skin cancers within three years. Factors including the age, gender, smoking status, skin colour, tanning ability, freckling tendency, and other aspects of medical history are covered by the quiz
5/25 Multiple Sclerosis stem cell treatment 'helps patients walk again'
A new treatment for multiple sclerosis (MS) has enabled some patients to walk again by “rebooting” their immune systems. As part of a clinical trial at Sheffield's Royal Hallamshire Hospital involving around 20 patients, scientists used stem cells to carry out a bone marrow transplant. The method known as an autologous haematopoietic stem cell transplant (HSCT) works by using chemotherapy to destroy the area of the immune system which causes MS
6/25 Dementia patients left without painkillers and handcuffed to bed
Dementia patients experience a ‘shocking’ variation in the quality of hospital care they receive across England, a charity has warned. Staff using excessive force and not giving dementia patients the correct pain medication were among the findings outlined in a new report by The Alzheimer’s Society, to coincide with the launch of Fix Dementia Care campaign
7/25 Cancer risk 'increased' by drinking more than one glass of wine or pint of beer per day
Drinking more than one glass of wine or pint of beer a day increases the risk of developing cancer, according to medical experts. New guidelines for alcohol consumption by the UK published by chief medical officers warn that drinking any level of alcohol has been linked to a range of different cancers. The evidence from the Committee on Carcinogenicity (COC) overturns the oft-held view that a glass of red wine can have significant medical benefits for both men and women
8/25 Vaping 'no better' than smoking regular cigarettes
Vaping could be “no better” than smoking regular cigarettes and may be linked to cancer, scientists have found. The study which showed that vapour from e-cigarettes can damage or kill human cells was publsihed as the devices are to be rolled out by UK public health officials as an aid to quit smoking from 2016. An estimated 2.6 million people in the UK currently use e-cigarettes
9/25 Rat-bite fever
A teenager was hospitalised and left unable to move after she developed the rare rat-bite fever disease from her pet rodents which lived in her bedroom. The teenager, who has not been named, was taken to hospital after she complained of a pain in her right hip and lower back which later made her immobile, according to the online medical journal BMJ Case Reports. She suffered for two weeks with an intermittent fever, nausea and vomiting and had a pink rash on her hands and feet. The teenager, who had numerous pets including a dog, cat, horse and three pet rats, has since made a full recovery after undergoing a course of antibiotics. Blood tests showed that she was infected with for streptobacillus moniliformis – the most common cause of rat-bite fever. One of her three pet rats lay dead in her room for three weeks before her symptoms showed
10/25 Taking antidepressants in pregnancy ‘could double the risk of autism in toddlers’
Taking antidepressants during pregnancy could almost double the risk of a child being diagnosed with autism in the first years of life, a major study of nearly 150,000 pregnancies has suggested. Researchers have found a link between women in the later stages of pregnancy who were prescribed one of the most common types of antidepressant drugs, and autism diagnosed in children under seven years of age
11/25 Warning over Calpol
Parents have been warned that giving children paracetamol-based medicines such as Calpol and Disprol too often could lead to serious health issues later in life. Leading paediatrician and professor of general paediatrics at University College London, Alastair Sutcliffe, said parents were overusing paracetamol to treat mild fevers. As a result, the risk of developing asthma, as well as kidney, heart and liver damage is heightened
12/25 Fat loss from pancreas 'can reverse' effects of type-2 diabetes
Less than half a teaspoon of fat is all that it takes to turn someone into a type-2 diabetic according to a study that could overturn conventional wisdom on a disease affecting nearly 3 million people in Britain. Researchers have found it is not so much the overall body fat that is important in determining the onset of type-2 diabetes but the small amount of fat deposited in the pancreas, the endocrine organ responsible for insulin production
13/25 Potatoes reduce risk of stomach cancer
Scientists have found people who eat large amounts of white vegetables were a third less likely to contract stomach cancer. The study, undertaken by Chinese scientists at Zhejiang University, found eating cauliflower, potatoes and onions reduces the chance of contracting stomach cancer but that beer, spirits, salt and preserved foods increased a person’s risk of the cancer
14/25 Connections between brain cells destroyed in early stages of Alzheimer’s disease
Scientists have pinpointed how connections in the brain are destroyed in the early stages of Alzheimer’s disease, in a study which it is hoped will help in the development of treatments for the debilitating condition. At the early stages of the development of Alzheimer’s disease the synapses – which connect the neurons in the brain – are destroyed, according to researchers at the University of New South Wales, Australia. The synapses are vital for brain function, particularly learning and forming memories
15/25 Sugar tax
The Government should introduce a sugar tax to prevent an “obesity crisis” from crippling the NHS, a senior Conservative MP and former health minister has said. Dr Dan Poulter believes that the case for increased taxes on unhealthy sugary products was “increasingly compelling”
16/25 Cancer breakthrough offers new hope for survivors rendered infertile by chemotherapy
A potentially “phenomenal” scientific breakthrough has offered fresh hope to cancer patients rendered infertile by chemotherapy. For the first time, researchers managed to restore ovaries in mice affected by chemotherapy so that they were able to have offspring. The scientists now plan to begin clinical trials to see if the technique, which involves the use of stem cells, will also work in humans by using umbilical cord material and possibly stem cells taken from human embryos, if regulators agree
17/25 Take this NHS test to find out if you have a cancerous mole
An interactive test could help flag up whether you should seek advice from a health professional for one of the most common types of cancer. The test is available on the NHS Choices website and reveals whether you are at risk from the disease and recommends if you should seek help. The mole self-assessment factors in elements such as complexion, the number of times you have been severely sunburnt and whether skin cancer runs in your family. It also quizzes you on the number of moles you have and whether there have been any changes in appearance regarding size, shape and colour
18/25 Health apps approved by NHS 'may put users at risk of identity theft'
Experts have warned that some apps do not adequately protect personal information
19/25 A watchdog has said that care visits must last longer
The National Institute for Health and Care Excellence (Nice) said home help visits of less than 30 minutes were not acceptable unless part of a wider package of support
20/25 Pendle in Lancashire tops list of five most anxious places to live in the UK
Pendle in Lancashire has been named the most anxious place to live in the UK, while people living in Fermanagh and Omagh in Northern Ireland have been found to be the happiest
21/25 Ketamine could be used as anti-depressant
Researchers at the University of Auckland said monitoring the effects of the drug on the brain has revealed neural pathways that could aid the development of fast-acting medications. Ketamine is a synthetic compound used as an off anaesthetic and analgesic drug, but is commonly used illegally as a hallucinogenic party drug. Dr Suresh Muthukumaraswamy, a senior researcher at the university and a member of the institution’s Centre for Brain Research, used the latest technology in brain imaging to investigate what mechanisms ketamine uses to be active in the human brain
22/25 A prosthetic hand that lets people actually feel through
The technology lets paralysed people feel actual sensations when touching objects — including light taps on the mechanical finger — and could be a huge breakthrough for prosthetics, according to its makers. The tool was used to let a 28-year-old man who has been paralysed for more than a decade. While prosthetics have previously been able to be controlled directly from the brain, it is the first time that signals have been successfully sent the other way
23/25 The biggest cause of early death in the world is what you eat
Unhealthy eating has been named as the most common cause of premature death around the globe, new data has revealed. A poor diet – which involves eating too few vegetables, fruits, nuts and grains and too much red meat, salt and sugar - was shown to be a bigger killer than smoking and alcohol
24/25 Scientists develop blood test that estimates how quickly people age
Scientists believe it could be used to predict a person’s risk of developing Alzheimer’s disease as well as the “youthfulness” of donated organs for transplant operations. The test measures the vitality of certain genes which the researchers believe is an accurate indication of a person’s “biological age”, which may be younger or older than their actual chronological age
25/25 Aspirin could help boost therapies that fight cancer
The latest therapies that fight cancer could work better when combined with aspirin, research has suggested. Scientists from the Francis Crick Institute in London say the anti-inflammatory pain killer suppresses a cancer molecule that allows tumours to evade the body’s immune defences. Laboratory tests have shown that skin, breast and bowel cancer cells often generate large amounts of this molecule, called prostaglandin E2 (PGE2). But Aspirin is one of a family of drugs that sends messages to the brain to block production of PGE2 and this means cancer cells can be attacked by the body’s natural defences
Explaining exactly why vitamin D supplements are often harmful is harder. Some people who don’t take supplements have naturally high blood levels which may be due to them spending large amounts of time outdoors in the sun or eating oily fish regularly – and there is no evidence that this is harmful. Higher than average levels can also be due to genes which on average influence about 50% of the differences between people. So our obsession with trying to bring everyone up to a standard normal target blood level is seriously flawed, in a similar way to our one-size-fits-all approach to diet.
Until now we have believed that taking vitamin supplements is “natural” and my patients would often take these while refusing conventional “non-natural” drugs. Our body may not view supplements in the same misguided way. Vitamin D mainly comes from UV sunlight converted slowly in our skin to increase blood levels or is slowly metabolised from our food. In contrast, taking a large amount of the chemical by mouth or as an injection could cause a very different and unpredictable metabolic reaction. For example, our gut microbes are responsible for producing around a quarter of our vitamins and a third of our blood metabolites and also respond to changes in vitamin levels picked up by receptors in our gut lining. Any artificial addition of large amounts of chemicals will upset some sensitive immune processes.
The news that even my favourite vitamin can be dangerous is a wake-up call. We should be taking our worldwide abuse of these chemicals much more seriously rather than routinely adding them to foods. The billions we waste on these products, assisted by the poorly regulated but rich and powerful vitamin industry should be spent on proper healthcare – and people should be educated to go in the sunshine and eat a diverse range of real food instead. For 99% of people, this will provide all the healthy vitamins they will ever need.