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