Dame Sally Davies, Dr Tony Jewell, Dr Michael McBride, and Sir Harry Burns England, Wales, Northern Ireland and Scotland's CMOs) wrote a letter to GPs, health visitors and community nurses to encourage better awareness of vitamin D guidelines and recommendations due to an alarming rise in illnesses linked to vitamin D deficiency.

The letter stated 'The National Diet and Nutrition Survey demonstrates that up to a quarter of people in the UK have low levels of vitamin D in their blood, which means they are at risk of the clinical consequences of vitamin D deficiency. It is important for public health that bw levels of vitamin D are avoided. As health professionals, you can make a significant difference to people's health by making those at risk aware of how important it is to make sure they get enough vitamin D, and how they can get access to mese important daify supplements. We, me Chief Medical Officers, thank you for your continued help and support with raising awareness of this issue, which in turn should raise the levels of vitamin D in those at risk, and vulnerable groups.'

The dangers of deficiency

Vitamin D deficiency impairs the absorption of dietary calcium and phosphorus leading to bone problems such as rickets in children and osteomalacia in adults.

The at-risk groups identified include pregnant and breastfeeding women; children aged under five; people aged over 65; and dark-skinned people who have little exposure to the sun. The letter urges people to be aware of the ways in which they can access vitamin D naturally, recommended guideline daily amounts of vitamins, and of the different schemes that provide supplements to eligible individuals.

Dame Davies said: 'A significant proportion of people in the UK probably have inadequate levels of vitamin D in their blood. People at risk of vitamin D deficiency, including pregnant women and children under five, are already advised to take daily supplements. Our experts are dear - low levels of vitamin D can increase the risk of poor bone health, including rickets in young children.1

Travelling back in time?

In the Victorian era rickets was a common ailment, but it was largely eradicated in the 1940s in the UK due to added fortifications of the vitamin to products like margarine and cereal. The most common cause of rickets is a lack of vitamin D and calcium.

In rare cases children can be born with a genetic form of rickets. It causes the bones to become painful, soft, and weak, leading to deformities of the skeleton, such as bowed legs, curvature of the spine and a thickening of the ankles, wrists and knees.

In older children, symptoms can include waddling when walking, bent bones, muscle weakness and pain. Rickets can be prevented by eating a diet that includes vitamin D and calcium and by spending some time in the sunlight.

The disease can be successfully treated in most children by ensuring that they eat foods that contain calcium and vitamin D or by taking supplements. A child may need a higher dose or a yearly vitamin D injection if they have trouble absorbing vitamins.

Sir Harry Burns, Scotland's Chief Medical Officer, said: 'Health professionals can make a significant difference to people's health by making those at risk aware of how important it is to make sure that they get enough vitamin D and how they can get access to these important daily supplements'.

It is thought that spending on vitamin D supplement prescribing, which has tripled from £28m in 2004 to £76m in 20 11, will continue to accelerate and will hit £100m this year.

Healthy Start

A programme that offers access to supplements is the Healthy Start scheme. Pregnant women, or families with a child under four who are on certain benefits qualify, as do all women under 18, whether or not they are claiming benefits.

The vouchers can be spent on milk, fresh or frozen fruit and vegetables, and infant formula milk. Pregnant women get one voucher per week (£3. 10); babies under two get two vouchers (£6.20); and children aged one to four get one voucher. Every eight weeks beneficiaries also receive green vitamin coupons with dieir vouchers, which they can swap for Healthy Start vitamins in their local area. The coupons are for the Healthy Start women's tablets or Healthy Start children's drops. It is the responsibility of the primary care and health trusts and health boards to make both of these products available locally to beneficiaries - and they may also sell them on to members of the general public if they wish to.

Dr Nick Harvey, spokesman for Arthritis Research UK and Senior Lecturer at the MRC Lifecourse Epidemiology Unit at the University of Southampton, said: 'We believe that more research is needed to understand the role vitamin D supplements play in optimising bone strength and what the correct level of supplementation is'.

One case in particular highlighted the crucial need for vitamin D in pregnant women. In a recent Old Bailey trial, a judge instructed a jury to find a couple not guilty of shaking their four-month-old baby to death, as a post-mortem had clearly shown that the baby was suffering from a severe case of rickets.

The rickets had caused the bones and skull to weaken and fracture very easily, mimicking the effects of deliberate shaking. The baby's mother had been found to have so little vitamin D in her body when pregnant that the baby had not received the vitamin either in the womb or through breastfeeding. Although this is an extreme example, it is a fact that a lack of vitamin D can be fatal in some circumstances.

The 'sunshine vitamin'

One factor affecting people's intake of vitamin D is likely to be covering up from the sun for fear of the health risks of being exposed to too much ultraviolet sunshine (UVB). Although the risks of melanoma should not be ignored or taken lighdy, small bursts are advised, as exposure to sunlight is the most effective way to absorb vitamin D.

British Dietetic Association spokesperson Laura Watson explains:

'"Vitamin D'" is an umbrella term used to describe the many forms of a fat-soluble steroid. Sometimes called the "sunshine vitamin'" most of our intake occurs as a result of the interaction between our skin and exposure to direct UVB sunlight. Our diet can also contribute, although to a lesser extent. We require vitamin D to help to maintain plasma calcium concentrations within the normal range.'

Regular, short periods of UVB exposure without sunscreen during the summer months are enough for most people; however, thanks to the unpredictability of the climate, air pollution, latitude, more time spent inside and the increased use of sunscreen when we do have sunny days, there is growing evidence of sub-optimum levels. Around 90% of our vitamin D is made in the skin with the help of sunlight, which converts the cholesterol found in every cell to the vitamin. Ideally, vitamin D levels should be around 75 nanomoles per litre of plasma (nmol/L) or more. Fewer than 25 nmol/L is considered deficient.

Arthritis Research UK Medical Director, Alan Suman, explains: 'Vitamin D is essential for strong, healthy bones. Our advice to people is to step outside, as this is the best way to get vitamin D. When the days are sunny, go out for a few minutes and expose your face and arms to the sunshine. Don't allow your skin to go red, and take care not to burn, particularly in strong sunshine and if you have fair or sensitive skin. From June to August just 15 minutes is generally enough time.'

Nick Harvey agrees: 'Young women and mothers can top up their vitamin D levels by getting enough sunshine on their skin - enjoying the sun safely, while taking care not to burn. The time needed to make sufficient vitamin D varies according to a number of environmental, physical and personal factors but it is typically short and less than the amount of time needed for skin to redden and burn. Eating a healdiy balanced diet, including more oily fish and foods fortified with vitamin D, such as breakfast cereals and some margarines can help. There is significant research to suggest that bone strength starts at birth or even in the womb. Arthritis Research UK is currendy funding research at Southampton University to prove that giving vitamin D supplements to pregnant women who are deficient in the vitamin can increase the bone density of their babies at birth and reduce the risk of their babies developing osteoporosis in later life.'

In a recent study, Caucasian British people were given a simulated dose of a summer exposure to sunlight, while dressed in casual summer clothes that revealed a third of their skin. These controlled conditions (die equivalent of 13 minutes of midday exposure to the summer sun given three times a week for six weeks during winter) raised 25(OH) D levels to greater than 50 nmol/L in 90% of people and greater than 70 nmol/L in 26% of people. The true amount of time may be greater and will vary depending on other factors including posture, time of day, outdoor activities, and the presence of shade.

The way forward

In Wales plans are already under way to improve the rate of vitamin D consumption. A government health spokesman said: 'The uptake of Healthy Start vitamins is lower than we would like in Wales, as in the rest of the UK. To address this, the Welsh government has been running a pilot in Cardiff to explore different approaches to the distribution of vitamins in order to maximise uptake.

'Results of the pilot so far have demonstrated a significant improvement. It has another six months to run, but following the evaluation of this work, the lessons learnt will be applied across Wales to improve awareness and distribution, and we hope will lead to a substantial increase in the uptake of Healthy Start vitamins, and hence the vitamin D status of some of those most at risk.'

However, a Scottish government spokesperson said: 'Given that research and surveillance data point towards inadequate awareness and intake within at-risk groups, our primary focus at present must be on encouraging compliance with current guidelines. We have no plans at this time to change the recommended levels of supplement.'

Author affiliation:

Chloe Harries

Assistant Editor