Written by: Brittani Kolasinski (BHSc Nut, AdvDip. NutMed)
With some of the world’s most beautiful beaches and predominantly most of Australia’s population residing along the coastal fringe yet there is a notable number of people having sub-optimal and even deficient levels of vitamin D. The Australian Bureau for Statistics (ABS) concluded that during the years of 2011 and 2012 approximately 4 million Australian adults were considered vitamin D deficient. It was found that 23%, or 1 in 4 Australians adults suffered some form of vitamin D deficiency (ABS, 2013).
We know for one, that we increase our levels through sun exposure, [through a complex procedure within the body which I won’t go into detail] but we also need to obtain this fat-soluble vitamin from dietary sources such as butter, egg yolks, fatty fish (salmon, mackerel, sardines) and dairy (Paxton, 2015).
So, what is the deal with vitamin D? and why do we need to have more than adequate levels? 50nmol/L is recommended to prevent osteoporosis, however optimal levels should exceed 100nmol/L and most of us are not hitting this mark.
Vitamin D is known for its benefits to our bones, maintaining skeletal homeostasis, however it is also a vital component of our immune system, acting as an immuno-modulator, targeting specific immune cells, which contain vitamin D receptors, including our T-lymphocytes, B-lymphocytes, dendritic cells and macrophages (Baeke et al, 2010).
“Several epidemiological studies have linked inadequate vitamin D levels to a higher susceptibility of immune-mediated disorders, including chronic infections and autoimmune diseases”
(Baeke et al, 2010).
Vitamin D adequacy can be attributed to telomere length… Studies found that those with lower vitamin D levels had shortened telomeres which correlated to additional years of age and subsequent cellular damage (Richards et al, 2007).
Side note: Telomeres are caps at the end of our DNA strands which protect our chromosomes and are a biochemical marker for aging and cell damage. As these telomeres shorten with every new cell division (which is occurring all the time throughout our lives) they ensure that the DNA remains intact. Eventually telomeres get to the point where they are too short to continue to function, this results in our cells to age and cease functioning properly themselves. Telomeres can therefore be considered as an aging clock in every cell within our body.
Deficiency of vitamin D is also associated with autoimmune disease (AID), occurrence of AID in Australia has also been increasingly apparent (AIDA Report, 2013). Low vitamin D levels has also been attributed to obesity through its mechanisms of influence on insulin secretion, as well as showing positive effects on blood sugar levels (Earthman et al, 2012; Alvarez & Ashral, 2010).
The purpose of this article is to educate on the many functions of vitamin D in humans, backed by research. As we can see there are a multitude of benefits of having optimal levels, however too much can be toxic to the body. If you’re wanting to increase or assess your own levels of vitamin D please consult with your health practitioner to get appropriate supplementation and dietary interventions for your own individual needs.
I am happy to have a consultation with you, if you haven’t found yourself a practitioner to work with. You can book online here
Yours in health,
Alvarez, J. A., & Ashraf, A. (2009). Role of vitamin D in insulin secretion and insulin sensitivity for glucose homeostasis. International journal of endocrinology, 2010.
Australian Bureau of Statistics, 2013, Australian Health Survey: Biomedical Results for Nutrients, 2011-12.
Baeke, F., Takiishi, T., Korf, H., Gysemans, C., & Mathieu, C. (2010). Vitamin D: modulator of the immune system. Current opinion in pharmacology, 10(4), 482-496.
Earthman, C. P., Beckman, L. M., Masodkar, K., & Sibley, S. D. (2012). The link between obesity and low circulating 25-hydroxyvitamin D concentrations: considerations and implications. International journal of obesity, 36(3), 387.
Paxton, F. (2015). Foundations of Naturopathic Nutrition.
Richards, J. B., Valdes, A. M., Gardner, J. P., Paximadas, D., Kimura, M., Nessa, A., ... & Aviv, A. (2007). Higher serum vitamin D concentrations are associated with longer leukocyte telomere length in women. The American journal of clinical nutrition, 86(5), 1420-1425.