Are you D-ficient? (Why we need vitamin D)
Photo: Unsplash
At this time of year – and in the midst of the pandemic – we all need to think about our levels of vitamin D. We know vitamin D as the ‘sunshine vitamin’, and that our bodies manufacture it after exposure to sunlight – the only vitamin that we don’t get solely from food. Vitamin D helps to regulate levels of calcium and phosphate in our bodies, which is needed for healthy bones, teeth and muscles.
Where we get vitamin D from
It’s tricky to get enough from food. Good sources include oily fish (salmon, mackerel, herring and sardines), and egg yolks. Some foods are fortified with vitamin D, including breakfast cereals, fat spreads and non-dairy milk alternatives like soya or oat. You can buy mushrooms rich in vitamin D, marketed by UK & Ireland Mushroom Producers; or up levels yourself by exposing mushrooms to strong sunlight.
Why we may need more vitamin D
Around one in five people in the UK have low vitamin D levels. Deficiency symptoms may include muscle pain and weakness, risk of fractures and osteomalacia (bone softening). In children, severe deficiency results in rickets, where the bones of the leg are deformed, causing them to bow outwards. This was virtually eradicated in the UK in the 1950s, but child food poverty is causing it to make a comeback.
In spring and summer, most people in the UK can generate enough vitamin D from being in the sun daily for short periods with forearms, hands or calves uncovered and without sunscreen, especially from 11am to 3pm. How much time in the sun is enough, depends on the strength of the sun and how much skin you’re showing.
But from October to March, the sun isn’t strong enough for our bodies to make it, so many of us risk deficiency. The NHS currently advises everyone to take a daily supplement of 10 micrograms (or 40 International Units, IU) through these months. Most good-quality vitamin and mineral supplements contain this amount – check the label.
Levels can be lower than normal in many people, including those who are overweight, and black and minority ethnic people, who might want to take a supplement year-round.
As we age, our skin gets thinner, which means it’s less able to synthesise vitamin D. During the first five years of menopause, we can lose nearly 10% of muscle mass, so getting enough vitamin D is crucial.
If you’re on statins to lower cholesterol you may be aware of the commonly reported side-effect of muscle pain. There has been some debate on whether these pains are actually a sign of vitamin D deficiency, since cholesterol is needed for the vitamin’s synthesis in the body.
Photo: Penn State University
Testing, testing
I decided to test my own vitamin D levels because writing this sparked my curiosity– and it would be silly to write about possible deficiency while unknowingly suffering it. As an overweight vegetarian, I’m at slightly higher risk, because I’m overweight and because many D-rich foods are of animal origin.
Current National Institute for Health and Care Excellence guidelines say health professionals shouldn’t test vitamin D levels unless there are symptoms of deficiency, so I tried BetterYou’s test kit, £32.95, including DLux Vitamin D Oral Spray at the right strength for your level (sent after testing). It arrived in a letterbox-fitting cardboard box, with comprehensive instructions on how to take a blood sample and drop four drops on the little card, an alcohol wipe and even a plaster. Because I am a wimp, I had to screw up my courage to stab my finger with the little spring-loaded lancet device. This punctured me perfectly, albeit a bit more painfully than a blood test by someone else. The results arrived within 10 days and I was relieved to see that I had the top status: ‘adequate’, above the levels ‘severe deficiency’, ‘deficiency’ and ‘insufficiency’.
Superdrug also sells a test for £36.
Covid and vitamin D
Another reason to take that supplement is because people with low vitamin D levels might be more at risk of catching Covid-19. Queen Mary University of London is currently carrying out a six-month home-based study of over 5,000 people on the effects of vitamin D supplementation.
Lead researcher Professor Adrian Martineau said: ‘There is mounting evidence that vitamin D might reduce the risk of respiratory infections, with some recent studies suggesting that people with lower vitamin D levels may be more susceptible to coronavirus. Vitamin D deficiency is more common in all of the groups who are at increased risk of becoming very ill with Covid-19.’
Principal investigator, Dr David Jolliffe, added: ‘The trial has the potential to give a definitive answer to the question of whether vitamin D offers protection against Covid-19. Vitamin D supplements are low in cost, low in risk and widely accessible; if proven effective, they could significantly aid in our global fight against the virus.’
Here’s hoping…
Adrienne Wyper is a health and lifestyle writer and regular TNMA contributor.
Discussion (12 Comments)
Thanks Ana, I wasn’t aware of this but will definitely do some more research.
Demelza says:
Alyson, may I recommend Grassroots Health which has a wealth of knowledge and information on Vitamin D
https://www.grassrootshealth.net/
Julia says:
Vit D is fat soluble (think of the natural foods which are high in Vit D) therefore it’s best to take a supplement with a meal containing fat. Also don’t forget other supplements (fish oil, multivitamins) already contain Vit D. Having said that, one would have to take vast doses, way in excess of most over the counter supplements, to overdose.
Lucy says:
You would really have to take a huge amount to overdose (very few cases on record). When I was pregnant a consultant (NHS) realised my levels were low (in the 20’s). I was immediately prescribed 35,000 IU (and then took that amount every week for the rest of my pregnancy). I now take around 6000iu a day and there is some emerging research that taking around 10,000iu a day for around 14 days if you test positive for Covid could help prevent the most serious complications/death etc.
Catherine Dempsey says:
This is of particular interest to me. I’m 74 and live in SW France where I get more than enough sun… and am addicted to tinned sardines, mackerel and salmon! Several years ago my GP gave me a prescription for a blood test including vitamin D assessment – they’re keen on prevention here, I had no obvious symptoms. I had a very low reading and she prescribed a once every three months disgusting concoction. It was extremely easy to forget to renew the prescription! At that point I started ordering from Healthspan, a UK company, a Vitamin D in an oil capsule and have taken one a day ever since. Recently I had another check up blood test and was delighted to see that my Vitamin D levels are totally normal. Have got husband on them too now. (I have no connection with Healthspan by the way, and just hoping that after 31/12/20 there is no problem with supply.)
Ana, you’re right: it is dangerous to take too much vitamin D. You shouldn’t take more than 100 micrograms (4,000 IU) of vitamin D a day. The daily amount recommended by the NHS, is 10 micrograms (400 IU). Unless you have severe deficiency, in which case you should consult your GP, you should not take more than 10 micrograms (400 IU) of vitamin D a day.
Once again thank you Alyson for writing about a very important health related issue. I live in Sydney – sunny Australia. In a number of our health areas in Sydney we are routinely giving women planning a pregnancy or who are pregnant and then their new born children Vit D supplements. Ladies keep looking after your physical health to live well and contribute to the well being of those around you.
Mrs Tonia says:
Thanks Adrienne and Alyson for this helpful article. Thus far I’ve relied on sitting in the sun and eating oily fish which I enjoy, fresh and tinned, several times a week. However this autumn/winter I may buy and use a vitamin D spray which I’ve seen available in a local health food shop. It’s useful to know what dosage to look out for. I don’t take regular vitamins apart from effervescent vitamin C tablets in winter months but this might be the season to start, having relied on good nutrition for my vitamins.
Katie Owen says:
I find the Vitamin D debate extremely confusing! Up until recently I believed it was important to take a Vitamin D supplement during the UK’s winter months. However, I just read Tim Spector’s (Professor of Genetic Epidemiology, King’s College London) excellent book entitled ‘Spoon-Fed: Why Almost Everything We’ve Been Told About Food is Wrong’. In his chapter covering vitamin supplements, Prof Spector says that he studied Vitamin D for 25 years and “believed it could prevent diseases, and that we should take more of it.” But six years ago he changed his mind and now suggests that for most people (with some medical exceptions), Vitamin D supplementation “does not work, and the risks outweigh any benefits.”
In a recent Liverpool John Moore University blog entitled: ‘What supplements do scientists use and why?’, Prof Spector commented: “After researching my book I realised that some clinical studies (when properly carried out and independent of the manufacturers) showed that they didn’t always work, and in some cases could be harmful. The only exception is supplements for preventing blindness due to macular degeneration, where randomised trials have been generally positive for a minor effect with a mixture of antioxidants.
“In many cases, there is some experimental evidence these chemicals in supplements work naturally in the body or as foods, but no good evidence that when given in concentrated form as tablets they have any benefit. Recent evidence shows that high doses of some supplements can even be harmful – a case in point being calcium and vitamin D. Rather than taking expensive and ineffective synthetic products, we should get all the nutrients, microbes and vitamins we need from eating a range of real foods, as evolution and nature intended.”
As a big fan of Prof Spector’s work – he is also leading the research on The Covid Sympton Study – I’ve taken his advice and ditched my Vitamin D supplement. But that’s my personal decision and others, I’m sure, will feel differently.
Thanks Katie for this informative input to the discussion. It’s interesting to hear that quality nutrition is preferable to supplements, unless one is truly deficient.
I’ve bought a vitamin D spray to try, child dose as above versus the adult dosage, and will keep up oily fish etc as well.
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Alyson, everyone should beware of excess intake; vitamin D is stored in the liver, not excreted through urine because it is not “hidrosoluble” ( I don’t know the translation); so an overload of vitamin D can be toxic. The dose should better be prescribed by a physician. I just wanted to add this to warn potential consumers.