Vitamin D is a fat soluble vitamin that has ‘hormone like’ actions in the body; making it is a very unique and important vitamin.
Vitamin D3 is made in our skin when we are exposed to the sun’s rays and, to a lesser extent, is found in some foods such as fish and eggs. Another form of Vitamin D (D2) is found in plants, however, it is thought that the body more readily utilises Vitamin D3 (1).
What are the benefits of Vitamin D?
Vitamin D is well known for its role in maintaining healthy bones by controlling levels of calcium in the body. More recently, however, Vitamin D has been shown to have an effect on a wide variety of other cells in the body and therefore may be important in other areas of health;
There is growing evidence that Vitamin D may be associated with chronic pain, e.g. lower back pain. A review of 19 studies looking at the effect on Vitamin D on pain concluded that a decrease in pain score was observed with Vitamin D supplementation compared to placebo (2).
Vitamin D appears to have an effect on a variety of different immune cells in the body; providing support to the immune system. Research on the effects of Vitamin D on the occurrence of respiratory tract infections, such as the common cold, has shown positive results (3).
Research has linked Vitamin D with mental health and mood. The research is still ongoing, however, it does show promise that Vitamin D supplementation in people with a known deficiency may be beneficial (4).
Fatigue is experienced commonly within the population and may be a result of many dietary and lifestyle factors. Vitamin D status is considered to be one potential factor. Studies have found that low Vitamin D is commonly found in people experiencing fatigue and that fatigue is improved following ‘normalisation’ of Vitamin D levels in the body (5).
In addition to the above areas, there are many other health conditions that have been associated with Vitamin D deficiency.
How to find out if you are getting enough Vitamin D?
The most effective way to evaluate your Vitamin D levels is to get them tested! Your GP and/or Nutritional Therapist can complete a simple test which lets you know your Vitamin D status. In short to be classed as having ‘sufficient’ Vitamin D, your test results should be over 50 nmols/l (6). The Vitamin D council, however, suggest that levels of between 100 – 200 nmol/l are ‘optimal’. They state most people should aim for a test result of 125 nmol/l. You can find out more from The Vitamin D Council here; https://www.vitamindcouncil.org
Who is at risk of Vitamin D deficiency?
National Surverys in the UK suggest that around 1 in 5 people have a deficiency in Vitamin D with blood levels below 25 nmol/l.
There are groups of people who have an increased risk of Vitamin D deficiency;
- People with darker skin
- People who spend a lot of time indoors during the day
- People who cover their skin all of the time; sunscreen or clothes
- Older people
- Pregnant women
How can you get more Vitamin D?
You can get Vitamin D from your diet, however, there are only few foods that contain Vitamin D and so you may not be able to meet your needs through food alone.
Foods that contain Vitamin D include;
- Beef liver
- Egg yolks
- Fortified food such as milk and cereals
Your skin produces Vitamin D when it is exposed to ultraviolet B rays (UVB) from the sun.
Between the months of March and September, being out in the sun every day for short periods between 11am – 3pm with forearms or legs uncovered and without sunscreen should give you enough Vitamin D. *It is important to ensure you do not burn your skin and get out of the sun before your skin starts to redden.
During the months of October to early March the sun doesn’t produce enough UVB rays for our skin to be able to make enough Vitamin D.
Vitamin D supplements should be considered in the following circumstances;
- For people ‘at risk’ (as explained above)
- For people who cannot get outside daily during March and September
- During the months of October and early march
Vitamin D is a ‘fat soluble’ vitamin that your body stores; this means that you CAN get too much! Knowing what dose of Vitamin D to take is therefore very important.
Public health England (PHE) recommend a supplement of 400IU of Vitamin D should be considered for everyone over the age of 5 between October and March and throughout the year for people with very little or no sun exposure.
Some organisations, such as The Vitamin D Council, believe that these guidelines are too low to support the population’s Vitamin D needs; they recommend a daily intake of 5000IU per day.
The European ‘tolerable upper intake’ or, in other words, the highest dose that is considered safe, is 4000IU per day.
When considering what dose of Vitamin D to take, it really depends on your personal ‘risk’ as well as your test results. Once you know your current Vitamin D status, you can then make a more informed decision on your course of action. Gain advice on sun exposure and supplementation, based on your test result, from your GP and/or Nutritional Therapist.
Vitamin D is only ONE potential factor in a persons diet and lifestyle. If you are experiencing anything that has been discussed in this article and would like to see how Nutritional Therapy may be able to support you, please contact us or make a booking for a FREE 15 minute consultation.
1 Tripkovic, L., Lambert, H., Hart, K., Smith, C. P., Bucca, G., Penson, S., … Lanham-New, S. (2012). Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis. American Journal of Clinical Nutrition, 95(6), 1357–1364. https://doi.org/10.3945/ajcn.111.031070
2 Wu, Z., Malihi, Z., Stewart, A. W., Lawes, C. M., & Scragg, R. (n.d.). Effect of Vitamin D Supplementation on Pain: A Systematic Review and Meta-analysis. Pain Physician, 19(7), 415–27. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/27676659
3 Martineau, A. R., Jolliffe, D. A., Hooper, R. L., Greenberg, L., Aloia, J. F., Bergman, P., … Camargo, C. A. (2017). Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. BMJ (Clinical Research Ed.), 356, i6583. https://doi.org/10.1136/BMJ.I6583
4 Spedding, S. (2014). Vitamin D and depression: a systematic review and meta-analysis comparing studies with and without biological flaws. Nutrients, 6(4), 1501–18. https://doi.org/10.3390/nu6041501
5 Roy, S., Sherman, A., Monari-Sparks, M. J., Schweiker, O., & Hunter, K. (2014). Correction of Low Vitamin D Improves Fatigue: Effect of Correction of Low Vitamin D in Fatigue Study (EViDiF Study). North American Journal of Medical Sciences, 6(8), 396–402. https://doi.org/10.4103/1947-2714.139291
6 Scientific Opinion on the Tolerable Upper Intake Level of vitamin D. (2012). EFSA Journal, 10(7). https://doi.org/10.2903/j.efsa.2012.2813