We’re well into the winter season and a lack of sunshine is probably something many of us notice quite regularly and complain about. That is why I chose to write about ‘the sunshine vitamin’ aka Vitamin D and its importance for our overall health.
Vitamin D is actually not a vitamin but a hormone. It is unique in that it is made in the skin as a result of exposure to sunlight. While the importance of Vitamin D in our overall health is unquestionable, sun exposure as a recommendation to satisfy our vitamin D requirements is a contentious topic. The sun has been demonized, and as a result, most of the world’s population has been brain washed into thinking that any exposure to sunlight is 'bad medicine'. There is no question that excessive exposure to sunlight and sun burning experiences are not good for us but sensible sun exposure is vitally important. Below is why.
Vitamin D is involved in a number of functions:
· Normal blood calcium levels
· Maintenance of bones and teeth
· Cell division
· The normal absorption / utilisation of calcium and phosphorus
· Maintenance of muscle function
· Immune system
· Growth and development of bones in children
It is now well documented that in the absence of any sun exposure vitamin D3 supplementation is necessary to maintain healthy levels of 25-hydroxyvitamin D in the circulation. The current daily recommendation for Vitamin D by Public Health England is 400iu but many health experts consider it too low. If you consider that the skin will naturally produce about 10000iu of Vitamin D in response to 20 – 30 minutes of sun exposure in the summer, you can understand why. Vitamin D is best supplemented as D3 (cholecalciferol) since this is the form produced naturally by the body in response to sunlight. Growing evidence suggests that vitamin D works in synergy with vitamin K and it is often recommended that they are supplemented together. You can have your Vitamin D levels checked by your GP or you can use independent labs like City Assays (http://www.cityassays.org.uk/vitamins.html) to assess your Vitamin D levels for a small fee.
Food sources of Vitamin D:
· Oily fish (e.g. wild salmon, sardines, tuna)
You might be pleased to hear that a large 2017 study published in the British Medical Journal found Vitamin D to be effective for preventing colds and flu – a reason good enough to prompt you to have your Vitamin D levels checked!
Jana of Vibrant You Ltd.
1. Martineau AR, Joliffe DA et al. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. BMJ 2017; 356: 16583
2. Michael Holick, http://vitamindhealth.org/
3. National Institutes of Health, http://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
4. The Nutrient Bible by Henry Osiecki (8th edition)
5. Vitamin D Council, http://www.vitamindcouncil.org/about-vitamin-d/what-is-vitamin-d/#
6. World’s Healthiest Foods, http://www.whfoods.com/