Vitamin D and the Immune System
Facts & Benefits of Vitamin D
We live on the sunniest continent on Earth, despite this as a population we are severely lacking in Vitamin D. For the last 30 plus years we have been warned of the sun’s ability to damage our skin and cause cancer and from this we have become a nation of people that fear that big burning ball. According to the Australian Bureau of Statistics more than 25% of Australians are Vitamin D deficient (<25 nmol/L) and more than 40% of Australians are Vitamin D insufficient (<50-75 nmol/L). So why does this matter? Well firstly, Vitamin D is not really a vitamin at all, it is actually a group of cholesterol-like substances. A significant role of Vitamin D is the regulation of Calcium; by facilitating the absorption of Calcium across the intestinal wall. In the absence of Vitamin D, dietary Calcium is very poorly absorbed. Vitamin D also supports cardiovascular health, bone mineralisation and immune function. For optimal health, a sufficient Vitamin D level of between 100-175 nmol/L is ideal, however I see very few people in clinic with levels within this range. There are many factors as to why this is the case, however the two most important:
- People are not getting adequate safe sun exposure to optimise Vitamin D synthesis in the body
- There is an impairment in the synthesis and conversion in the body to the activated form of Vitamin D; this can be due to age, weight, skin colour, or organ impairment such as liver dysfunction or illness
How can it support your immune system?
Vitamin D has been used to support the immune system since Hippocrates first prescribed sunlight to treat tuberculosis in Ancient Greece (circa 400 BC). Vitamin D enhances the immune system’s response by promoting macrophage activity. Macrophages are big eater cells, responsible for ingesting pathogens and microscopic debris and initiating targeted immune responses. Vitamin D also influences cytokine production, supporting immune cells. Cytokines aid the immune response by supporting cell to cell communication, stimulating the movement of cells towards the infection or pathogen. Through these mechanisms we know that Vitamin D enhances immune response through both viral and bacterial infections, for this reason alone, Vitamin D is a potent immune nutrient when it comes to fighting upper respiratory infections. Additionally, a deficiency in Vitamin D is also associated with some autoimmune conditions such as MS, Type 1 Diabetes and Crohn’s Disease. Whilst autoimmune status is multifactorial, the important role Vitamin D has on the immune system indicates it is a significant marker in these conditions.
Vitamin D for health
Whilst Vitamin D can be found in some foods such as cod liver oil, salmon, sardines, and beef liver; uptake can be unreliable. Most Vitamin D is produced inside the body following sun exposure, through an activation process involving the liver and kidneys. For some people this process can be impaired; this could be due to restricted sun exposure or for those who are immunocompromised or suffering from ill-health, either way supplementation of Vitamin D may be indicated. The best way to do this, is to have your levels checked regularly to ensure you are sitting above 100 nmol/L.
If you feel you would benefit from supplementation or would like more information on the benefits of Vitamin D, we would love to help you. Give the clinic a call on 02 4961 4075 and chat with a practitioner about your Vitamin D needs in a free mini phone consultation with a qualified practitioner.
Yours in health,
Samantha Wilson
