SYMPTOMS OF VITAMIN D DEFICIENCY
BEAT THE WINTER BUGS
I can’ t write an article on immunity without giving some well-deserved limelight to some exciting new research:
One vitamin that has got sports medicine, scientists and performance nutritionists all over the world excited is Vitamin D. The way this intriguing seco-steroid acts puts it into the TAKING DIRECT ACTION category in your defence against respiratory tract infections. Scientists identified that vitamin D doesn’ t just work to keep your bones healthy, it also modifies how your immune system responds when you are exposed to viruses and that when your levels drop, this could be leaving your immune system more vulnerable.
It turns out that it’ s no coincidence we get more respiratory infections during the winter months. For the six months between October and April 90 % of the UK lies too far north to allow our skin to be exposed to the UVB wavelength from the sun that is necessary for Vitamin D synthesis in human skin. In other words, you can’ t make your own Vitamin D during winter if you live in the UK; you are reliant on the stores you have built up through summer.
As we go through each month of winter our stores are gradually used up in all the many processes that Vitamin D is needed for day to day. If your stores are not enough to see you through to springtime, studies have shown you are at higher risk of getting acute respiratory tract infections
( BMJ)
. This explains in part, why some athletes might be more resilient than others; because they have better stores of Vitamin D to help in the defence against respiratory tract infections.
So how would you know if your levels are high enough? The most reliable way is to have a blood test, which although quick and easy to do( a service which is available nationally) it is not necessary for most people unless you are experiencing symptoms as well as risk factors.
I imagine most people reading this magazine will find they have least two risk factors; in fact, unless you take action, it is likely that your level WILL drop low during the winter months leaving you at higher risk of infection and potentially muscular and bone health issues. Because of this, Public Health England now recommends everyone over the age of 1 year living in the UK considers taking a supplement of 10micrograms( 400IU) Vitamin D daily throughout the autumn and winter months( PHE). This dose is considered to be enough for most people and can be found in products purchased from pharmacies and health food shops. If you already take a multivitamin or other supplements, check whether they contain vitamin D and in what quantity.
Some people won’ t need to take a supplement; for example, if you spend time in sunnier climates during winter, because there you will top up your stores via the sun. Conversely, some people will need to take a higher dose of vitamin D, but whether you need higher, and exactly how high should be determined from a blood test and / or under recommendation from a professional.( If you are particularly worried about your levels you can contact me directly to arrange blood tests and a personalised nutrition prescription).
In my article in last months M & F about supplements I advocated always using the‘ food first’ approach, so at this point you might be asking yourself:“ Can’ t I just eat food that is high in Vitamin D?” This would be the ideal but unfortunately not many foods naturally contain Vitamin D and those that do; oily fish( sardines, mackerel) and eggs, have only a small amount which is not enough to reach the requirements. So in this case, a supplement it has to be.
SYMPTOMS OF VITAMIN D DEFICIENCY
• Impaired immunity
• Muscle pain
• Tiredness / weakness
• Seizures
RISK FACTORS FOR INADEQUATE VITAMIN D LEVEL
• Living in the UK or anywhere as northerly
• Wearing high SPF sunscreens during summer( this is essential to prevent skin cancer, so don’ t stop)
• Wearing clothes that covers the skin
MARCH 2018 / MUSCLE & FITNESS 95