If you regularly engage in physical activity it’s important to take care of your body with the right nutrition. As well as increasing our wellbeing and energy levels, vitamins and minerals have the ability to help protect against injury and ensure good muscle recovery.
Unlike vitamins A, B and C, which are primarily obtained from foods, vitamin D is mainly produced by the action of sunlight on the skin. Here we talk to Dr David Mantle, medical adviser at nutrition expert Pharma Nord about the role of vitamin D and how it could improve your health and fitness.
- What is vitamin D and why is it important?
How much do you know about vitamin D? According to a health survey, 46 per cent of people think they get enough of this vitamin from vegetables. In fact, the majority must be obtained from strong sunlight, which is why many of us become deficient, particularly during the winter months. For this reason, vitamin D has earned its name as the ‘sunshine’ vitamin.
Vitamin D is extremely important for good health, playing a fundamental role in strong bones and teeth, supporting our immune system and even improving our mood. There is also evidence to suggest that vitamin D is important to help to protect against injuries and support muscle function during and after exercise. Vitamin D3 (cholecalciferol) is indentical to the kind produced naturally in our skin and can be taken in supplement form.
- What are the best sources of vitamin D and am I getting enough?
Around 90% of vitamin D must come from sunlight. Small quantities can be found in foods such as:
- Oily fish such as salmon, sardines, trout and kippers contain reasonable amounts of vitamin D.
- Eggs, meat and milk contain small amounts but this varies during the seasons.
- Margarine, some breakfast cereals and some yoghurts are ‘fortified’ with vitamin D.
Many people are deficient in vitamin D, with statistics suggesting that up to 50 per cent of UK adults are deficient. The highest rates of deficiency are found in Scotland, Northern England and Northern Ireland, due to limited sun exposure.
Sunbathing or working in the garden on a bright summer day can enable your body to make 5000IU of vitamin D, but how often do we get the chance? Due to limited sun exposure between October and March, it is almost impossible to get the UV rays needed to reach the daily requirement.
While we should all consider our vitamin D levels, those at greatest risk of deficiency are people aged over 65, pregnant and breastfeeding women, those who spend large amounts of time indoors, dark-skinned ethnic minorities and children.
A recent survey by Pharma Nord involving 650 UK adults suggests that our ‘indoor culture’ could be placing many of us at risk of vitamin D deficiency. One third of those surveyed admitted to spending less than an hour per day outdoors.
Those who follow a strict vegan diet also risk deficiency because many of the food sources are animal-based.
- What are the main health benefits?
Vitamin D is particularly important for maintaining healthy bones and teeth. Without it, calcium cannot be effectively absorbed by the body. A deficiency in vitamin D can result in bone and muscle pain, poor bone mineralisation (softer bones) and a greater risk of osteoporosis and fractures as we age. Research has shown that one in three women and one in five men over the age of 50 will suffer from bone fractures resulting from poor bone health. It is never to early to think about these potential risks in later life.
Vitamin D is also important for immune health. In fact, vitamin D3 may be more effective than vitamin C for boosting immunity and protecting against colds and flu. For example, studies in Finland and Japan showed that adults and children who had adequate vitamin D levels were less likely to suffer from respiratory illnesses. This could be because vitamin D stimulates the cells of the immune system which provide the body with a natural defence against infection.
Low mood has also been linked to vitamin D deficiency. Connections have been made between low vitamin D levels and seasonal affective disorder (SAD), a form of depression that usually begins in the Autumn and continues throughout the winter months. Symptoms can include feeling sad or anxious, fatigue, concentration problems, irritability and feelings of guilt and hopelessness. Although its exact cause is unclear, numerous studies have suggested that the condition may be triggered by a lack of sunlight.
Recent research has shown that vitamin D is also important for the normal functioning of the cardiovascular and digestive systems.
Research has linked good levels of vitamin D to reduced inflammation and pain within joints, as well as improved exercise capacity and better protein synthesis within the muscles. This means muscles are able to recover more effectively from intense exercise.
Low levels of vitamin D are associated with increased likelihood of illness and fatigue, which have obvious repercusions for sporting performance. Those with low vitamin D levels have also been found to have a higher risk of suffering stress fractures, which can result from weak bones and repetitive loading.
- Any tips on what to look out for if choosing a supplement?
When choosing a vitamin D supplement, look for vitamin D3 (cholecalciferol) as it’s identical to the form produced naturally in the skin. Vitamin D is an oil-soluable vitamin so try to avoid dry, chalky tablets as they are less easily absorbed by the body. Many nutritional experts recommend a daily intake of at least 800 IU.
A recent study highlighted the variability in vitamin D product quality from different manufacturers (Journal of the American Medical Association). There was a wide variation in vitamin D content, with some products having less than 10% of the vitamin D content stated on the label. Consumers should always purchase supplements manufactured to pharmaceutical standards, a guarantee of quality and accurate dosage
You could try Pharma Nord’s Bio-Vitamin D3, which contains vitamin D3 dissolved in cold-pressed olive oil and encapsulated in small, easy-to-swallow “pearls” of soft gelatine. There are three strengths available from www.multivits.co.uk including 800IU, 1000IU and 5000IU.