Ensuring you are achieving adequate nutritional and vitamin intake is important all year round but there are a few supplements that are particular important to stock up on during the winter season.
This has received wide spread media attention of late, and it is believed by many within the health and medical industry that we're amidst a vitamin D deficiency pandemic.
Advice on vitamin D from Public Health England (PHE), says that adults and children over the age of one should have 10 micrograms (mcg) of vitamin D every day, which equates to 400IU. Some studies suggest that a higher daily intake of 25–100 mcg or 1000 - 4000 IU is needed to maintain optimal blood levels.
As these levels are difficult to achieve through diet alone experts recommend that everyone consider vitamin D supplements. As our main source of vitamin D is from the action of sunlight on our skin, it's particularly important to supplement over the winter when exposure to sunlight is limited.
Vitamin D deficiency has been linked to a lowered immune system as it directly interacts with the cells that are responsible for fighting infection. Several large observational studies have shown a link between a deficiency and respiratory tract infections like colds, bronchitis and pneumonia.
Other deficiency symptoms include feeling tired, bone and back pain, muscle pain, low mood and depression, impaired wound healing, bone and hair loss,
Vitamin C & Zinc
For many years Vitamin C has been thought as the number one home remedy for keeping colds at bay. However, research within the last decade has found that taking vitamin C everyday does not reduce a person’s risk of getting one, but it does lessen the severity of a cold's symptoms and shorten the duration of the illness. Therefore getting sufficient amounts of the vitamin is particularly important during winter when there is a spike in people suffering a cold.
Graham Keen, executive director of the Health Food Manufacturers Association said:
"...a large-scale Cochrane meta-analysis published in 2013 found that regular vitamin C supplementation seems to have a consistent effect in reducing the duration and severity of common cold symptoms.
“It is also important to note that these products are not designed for curing or preventing the spread of disease. Daily vitamin supplements provide important nutritional insurance for millions of users looking to safeguard their nutritional intake alongside a healthy diet.”
Adults (19-64 years) need 40mg of vitamin C a day, but taking less than 1,000mg of vitamin C supplements a day is unlikely to cause any harm. It's important to note that vitamin C can't be stored in the body so is needed as part of your daily diet.
Zinc also has a role in reducing the duration and severity of a cold - a Cochrane review published in 2011 provided convincing evidence from more than a dozen placebo controlled trails that taking zinc soon after the onset of symptoms of the common cold significantly reduces both the duration and severity of symptoms.
The amount of zinc you need is about 9.5mg a day for men (aged 19-64 years) and 7mg a day for women. Don't take more than 25mg of zinc supplements a day unless advised to by a doctor.
Please note taking high doses of zinc reduces the amount of copper the body can absorb. This can lead to anaemia and weakening of the bones.
The B vitamins are a group of 8 vitamins sometimes called the “anti-stress vitamins” since they’re essential for combating the effects of stress. They are used to create the feel-good neurotransmitters responsible for maintaining a positive mood as well as being critical for a healthy nervous system.
The role of vitamin B12 in particular, could help us during the colder months as it has been shown to help those suffering from feelings of anxiety or depression. This is particular important during winter when people are more at risk of feelings of depression, winter blues or seasonal affective disorder (SAD).
It is found almost exclusively in animal protein sources - meat, poultry, seafood, dairy, and eggs - therefore vegans are at risk of deficiency as it's unlikely they will be able to obtain sufficient amounts through diet alone. In supplement form vitamin B12 is known as methylcobalamin, cyanocobalamin or adenosylcobalamin. The body actually converts cyanocobalamin into methylcobalamin making the latter more readily bioavailable - meaning it is more easily absorbed in the body.
The UK government says adults need 1.5 micrograms (mcg) a day and the European Food Safety Authority says 4mcg a day is adequate. The US and Europe, but not the UK, recommend higher levels for pregnant and breastfeeding women. A study published last year found one in 12 women aged between 19 and 39 were B12 deficient, despite consuming at least the UK recommended minimum intake.