Like all vitamins and minerals, Vitamin D has numerous roles in your body, too many to list in this small article. Some of the more important and well researched roles are …
- It is essential for a healthy immune system
- It helps regulate calcium and phosphate absorption and regulation for healthy bones, teeth and muscles
- It is anti cancer
- It is important in regulating blood clotting
- It protects against rickets, which is softening and weakening of bones in children
- It is a powerful anti oxidant
Vitamin D is a vitamin, right? Wrong!
In actual fact, Vitamin D is not a vitamin – it is a hormone which is made from exposure to sunlight. When you are exposed to ultraviolet B (UVB) rays, these rays hit cholesterol in the skin cells and start the synthesis of Vitamin D. It is then sent to the liver to be converted into 25-hydroxy vitamin D, which is inactive. The kidney then converts it into 125-dihydroxy vitamin D, which is the active form. Complicated isn’t it! As you will read later, the fact that it is a hormone, not a vitamin, is very important to understand why most people are deficient in Vitamin D.
What are the health risks if your levels of Vitamin D are low?
Again, there are many health risks associated with low Vitamin D levels, too numerous to mention in this article, but I will discuss the most researched health risks below.
Immune function.
Without adequate levels of Vitamin D, your immune system will always struggle. Research has shown that low Vitamin D levels increase your risk of acute respiratory tract infections, of catching frequent colds and flu and of wounds not healing properly. But if you think that your immune system is functioning well because you don’t catch colds often, you may have to think again because research has also shown that low levels of Vitamin D put you at higher risk of autoimmune diseases. Autoimmune diseases (there are over 100 of them), such as Rheumatoid Arthritis, Hashimoto’s, Grave’s disease, Psoriasis, Crohn’s disease, Ulcerative Colitis, Multiple Sclerosis, are caused by an immune system that becomes OVER stimulated and starts to attack the body. Doesn’t make a lot of sense does it? That low Vitamin D can lead to both under and over stimulation of the immune system. Just shows you how complicated your body is.
Bone health
Low Vitamin D levels can lead to osteoporosis (reduction in bone mineral density), Osteomalacia (softening of the bones) and Myopathy (muscle weakness and pain) by interfering with calcium and phosphate absorption. In children, Rickets is a more commonly known condition caused by Vitamin D deficiency. Rickets causes a softening of the bone, often leading to bow legs, delayed growth and weakness and pain.
Mental health
Research time and again has shown that low Vitamin D levels are linked to depression and high levels of stress and anxiety. Many people living in countries further from the equator suffer from a severe mood disturbance called Seasonal Affective Disorder (SAD). SAD is caused by Vitamin D levels reducing during the winter months.
Heart health
Low levels of Vitamin D have been linked to an increased risk of cardiovascular disease. The risk of hypertension, heart failure, stroke and ischemic heart disease (when the heart is not getting enough blood and oxygen) is increased when levels are low.
Diabetes
Research has shown that Vitamin D helps to improve the body’s sensitivity to insulin. Insulin is the hormone that regulates blood sugar levels and Type 2 Diabetes occurs when the body becomes resistant to insulin. So, ensuring adequate levels of Vitamin D can help prevent Type 2 Diabetes.
Cancer
There have been many studies over many years that link low levels of Vitamin D to various cancers. One such study published in The American Journal of Public Health quoted “The high prevalence of Vitamin D deficiency, combined with the discovery of increased risks of certain types of cancer in those who are deficient, suggest that Vitamin D deficiency may account for several thousand premature deaths from colon, breast, ovarian, and prostate cancer annually.” Ironically, in an era where everyone is told to keep out of the sun, studies have also shown a strong link between low levels of Vitamin D and melanoma.
What should your levels of Vitamin D be?
When Pathology labs calculate a reference range for their blood tests, the bottom of the reference is the point where people are likely to show symptoms of a deficiency. In general, a Doctor will read these results and not be concerned as long as the result is within the reference range. In Australia, the bottom of the reference range for Vitamin D3 is 50 nmol/L. That means that anything under 50 is classed as a deficiency and anything over 50 is classed as within range. But that doesn’t make any sense – it says that if your level is 51, then it is still within range, and therefore by default not a problem but at 49 it is a problem. What we should be looking at is optimal range, which is the range that will confer good health. Optimum levels of Vitamin D3 are between 120 – 150 nmol/L
Why are most people low in Vitamin D?
As a Naturopath, when clients ask me questions about what should they eat and why our levels of certain nutrients are often low, I point out that the society we live in really is artificial. We need to go back to what hunter and gatherers were doing because that is how our body has been genetically designed. We were always exposed to sunlight – no airconditioned offices and houses, no sunscreen and slip slop slapping. The message mainstream media has given us for decades is to stay out of the sun and this is the opposite of what our bodies are designed for. We need to sun to produce Vitamin D. With people now being able to travel anywhere in the world, we obviously need to be mindful that someone whose origins are from the colder climates of Europe who now live in the heat of Australia won’t tolerate the sun as much as someone whose origins are from the warmer climate. So common sense must prevail.
Another major reason that most people are deficient in Vitamin D is the constant low (and high) levels of stress that people live with. As mentioned above, Vitamin D is actually a hormone. Again, let’s go back to how our body has been designed. Our body recognises stress and anxiety as being life threatening – the threat of an animal or another human. We then produce a hormone called Cortisol. This triggers the “fight or flight” response by diverting blood flow to the arms and legs so we can literally either fight or run. Our body doesn’t know the difference between life threatening stress and emotional stress, and because most people live with a pretty much constant underlying stress, our body is constantly producing cortisol. There are only so many building blocks to make hormones, and because our body classes producing cortisol (because it thinks the constant stress is life threatening) as being priority, the other hormones including Vitamin D are put on the back burner. We need to reduce our chronic underlying stress in order to increase the amount of Vitamin D being produced.
Another reason for poor levels of Vitamin D is that our liver and kidney are needed to convert the Vitamin D to its active form. With chemicals, air pollution and alcohol putting a strain on our kidney and liver, the ability to convert Vitamin D is diminished.
Being overweight is another reason for low levels of Vitamin D. Research published in 2013 concluded that every 10% increase in BMI will lead to a 4.2% decrease in blood levels of Vitamin D.
The unfortunate fact is that in order to live in our artificial society, we need to supplement with Vitamin D to keep our levels optimum. It is important to have a blood test done to ascertain your levels before supplementing.
References:
httpshttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC6920963/://www.cancernetwork.com/view/does-vitamin-d-have-role-cancer-prevention