Sarah’s health notes: Vitamin D – do you need a supplement?
In May 2019, geneticist Professor Steve Jones came out about his vitamin D habit. ‘I used to be very sceptical about supplements of any kind. But it’s clear that taking a vitamin D supplement can be helpful, indeed essential, because many people in Britain, particularly in Scotland, have very low levels of vitamin D due to the shortage of sunlight and that puts them at risk of some severe diseases. I take it [a vitamin D supplement] and I will continue to take it … as an insurance policy,’ he said.
Vitamin D is often called the ‘sunshine vitamin’ – although it’s actually a hormone - because it’s synthesised in the skin by the action of sunlight, specifically UVB, as Professor Jones explains in his (fascinating and very readable) book Here Comes The Sun, just out in a new paperback edition.
‘The evidence that the shortage of sunlight has drastic effects on health is overwhelming,’ says Professor Jones. ‘Vitamin D deficiency affects life expectancy and is reflected in many conditions.’ As well as affecting our bones, teeth and muscles, there is a link with multiple sclerosis, also infectious diseases and heart disease – sunlight relaxes your blood vessels and drops your blood pressure. It also affects mood and is a factor in depression.
Getting out in sunlight is the best and most natural option but, due to our climate, lifestyle, ageing and sometimes living conditions (eg people in care homes), Vitamin D deficiency is widespread in the UK. The NHS estimates that about 22% of adults (one in 4-5) and the same number of children have low levels of vitamin D, more in the winter and spring. Deficiency is more common in people with darker skin due to melanin in the skin acting as a natural barrier to UVB. Being overweight or obese tends prevents the absorption of vitamin D as it accumulates in excess fat tissues and isn’t readily available when needed.
In April this year, Public Health England said everyone should supplement with 10mcg/400iu vitamin D daily, not just at risk groups. That dose is widely considered by experts to be very low (see below for guidelines). Although some foods – such as oily fish, egg yolks, red meat and fortified cereals/spreads - contain vitamin D, it’s difficult to get the recommended amount from food alone, according to the NHS. (You can probably get about 10% if you eat carefully.)
Vitamin D is important to keep your immune system robust, which has led to it being considered as a possible preventive agent and/or adjunctive treatment for Covid-19. Professor Adrian Martineau, an expert in respiratory infection and immunity at Queen Mary University of London, told The Guardian: ‘Vitamin D could almost be thought of as a designer drug for helping the body to handle viral respiratory infections. It boosts the ability of cells to kill and resist viruses and simultaneously dampens down harmful inflammation, which is one of the big problems with Covid.’ A Rapid Evidence Review by British regulatory bodies, which reported end June, says there is currently no conclusive evidence that vitamin D can prevent or treat Covid-19. But the (very rapid) review was based on limited data and research is ongoing, including a meta-analysis due in July from Professor Martineau’s group.
Regardless of the review, the regulatory bodies urge us to go on taking our daily supplements because of the importance of vitamin D for our physical and mental health.
So how much vitamin D do you need to take? And what type?
Many experts, including Professor Jones, believe that the NHS-recommended 10mcg (400iu) dose is very low. Women doctors I know are taking 2000iu daily. One thing here: supplements come in two forms D2 and D3, the latter is the one produced in the body and recommended as a supplement.
Leading brand BetterYou has worked with the NHS home testing service and says that research ‘supports a daily maintenance dosage of 25mcg (1000iu) for every 25kg of body weight’. For people in the UK, that works out at:
• 10mcg (400iu) for infants and toddlers under five years
• 50mcg (2000iu) for an average woman
• 75mcg (3000iu) for an average male
My husband has his BetterYou DLux 3000 Daily Vitamin D Oral Spray by his breakfast plate so he can dose himself every morning. (He prefers a spray to taking pills and studies show this method is well absorbed.) I have a couple of squishes of DLux 1000 Spray, £7.35. Each of these sprays delivers 100 individual doses, so it’s good value; I’m about to send them off to my niece and nephew and our office team.
Just a couple more things! My brother had Parkinson’s disease and when I talked to the medical director of Parkinson’s UK he insisted on the importance of vitamin D supplementation for patients, because of their increased risk of osteoporosis.
Secondly, the reality of vitamin D deficiency was brought home to me by observing a colleague before she was tested by her GP and after she was put on a short intensive supplementation regime followed by a daily maintenance dose. She had felt tired and lacking in energy for over six months, and had also suffered dizzy spells and joint pain. After her GP tested for a range of problems, he told her she was ‘massively lacking in vitamin D’ and prescribed a rapid correction daily supplement. After ten days, she told me: ‘I feel so much better. I have more energy and don't feel tired when I wake up.’ (Testing for vitamin D level involves a simple inexpensive blood test.)
My colleague had no idea her ill health could be down to vitamin D deficiency. Possible symptoms include fatigue and generalised weakness, depression, mood changes and irritability, blood sugar issues, low immunity, weight gain and low calcium levels in the blood, as well as bone softening (low bone density) or fractures, muscle cramps and joint pain (most noticeably in the back and knees), also hair loss. Additionally, sufferers of irritable bowel syndrome tend to be low in vitamin D and there are links with menstrual cycle disorders and infertility.
