Vitamin D: The Key To Your Immunity
Many of us are familiar with vitamin D – we know that it builds strong bones and teeth. But if we are serious about our health, there is much more about vitamin D that is important to know.
First of all, vitamin D is not actually a vitamin since we don’t require it from food sources. Instead, it is technically a hormone, since our bodies can make it when our skin is exposed to sunlight – hence its nickname “the sunshine vitamin”.
By regulating levels of calcium and phosphorous in the blood, vitamin D is necessary for adequate bone density, muscle contraction, the regulation of our heartbeat and the general functions of all cells of the body. It reduces inflammation, and is required for proper function of thyroid hormone. Receptors for vitamin D have been found in the thymus, bone marrow, breast, colon and brain, which suggests potential effects in these areas too. In fact, many regions of the brain are able to synthesise the active form of vitamin D, highlighting the importance of this nutrient for our brain function and mood. Studies of Vitamin D have found associations between low levels of Vitamin D and the prevalence of thyroid disorders, Alzheimer’s, cognitive decline, diabetes, heart disease, depression, increased susceptibility to infections and various cancers. There has been particular success with using vitamin D for the treatment of respiratory tract illnesses.
However, what I want to focus on in this article is the role of vitamin D in the functioning of our immune system.
The function of the immune system
The main function of the immune system is to protect us against infection and the development of cancer. According to the Encyclopedia of Natural Medicine (Murray & Pizzorno), “support and enhancement of the immune system is perhaps the most important step in achieving resistance to disease and reducing susceptibility to colds, flus, and cancer”.
However, the immune system is often overlooked in the overall picture of health. Let me digress by briefly mentioning the Germ Theory of Louis Pasteur, on which much of modern medicine is based. This theory sees the body as being at the mercy of harmful external microbes, which we need to kill to protect our health. And so we have antibiotics. At the same time however, a very different theory was put forward by Antoine Bechamp: the Terrain Theory. This theory emphasises the importance of our own internal “terrain” – that is, our own defence mechanisms and our body’s ability to maintain a healthy homeostasis. It is only when this normal functioning gets disturbed that disease can set in. This theory suggests that in a properly functioning body, disease is simply not possible.
We all know that Pasteur’s influence won out and Bechamp was largely forgotten. However, I think there is a lot of value to be gained from taking elements of the Terrain Theory and reflecting on them. Surely, by supporting our body’s systems and helping them work the way they are meant to, shouldn’t we be stronger and healthier?
Which brings me back to the immune system. Antibiotics, antiseptic hand sanitiser, chlorinated city drinking water… all of these certainly have their place, but I think we also need to look inward.
Signs of a compromised immune system
- You catch colds easily and/or get more than two colds a year
- You suffer from constant and chronic infections
- You get frequent cold sores, Candida outbreaks or allergic reactions
- Your lymph glands tend to be sore and swollen
- You suffer from an autoimmune condition
These can be signs of either an underfunctioning or a hypersensitive immune system, both of which are not ideal. We need the cells of our immune system to be strong enough and specialised enough to recognise a foreign invader and be able to destroy it; however we do not want it to be so vigilant that it starts to attack our own tissues because it loses the ability to discern between what is foreign and what is self. It needs to be strong yet kept in check.
Our immune system can be depleted by many things, including:
× sugar
× alcohol
× nutrient deficiencies
× stress
× depression
× use of antibiotics
The role of vitamin D
Since it is fair to say these detrimental factors are ubiquitous in our society, this is where vitamin D can be of benefit for us. Vitamin D is one of many hormones involved in the maturation and activation of white blood cells which then defend us against infection. These mature cells also contain receptors for vitamin D and are capable of making active vitamin D from the inactive form that travels in the blood, further indicating the important place of vitamin D in immune function. So it helps strengthen our immune system.
However vitamin D also modulates, or balances, the immune system. This means that as well as being capable of stimulating the immune system, it can also calm down an immune response when needed, such as in the case of allergies and sensitivities. It affects the way immune cells are trained to respond to antigens, so that they learn to attack only what is foreign, and not damage the body’s own tissues. Therefore vitamin D seems to be central to preventing the onset of autoimmune disease and is even able to at least partially reverse autoimmune processes once they have begun. Also, vitamin D regulates cell division, cell growth and cell numbers, so it is currently being investigated as a treatment for controlling the growth of cancers.
Vitamin D derivatives, such as calcipotriene, have been used successfully as part of treatment for autoimmune skin conditions including psoriasis. They have also shown particular promise for other autoimmune conditions including multiple sclerosis, rheumatoid arthritis and lupus.
Increasing your levels
If you have decided that vitamin D is something you want more of, you will be happy to know vitamin D must be one of the easiest supplements you can take. You have 3 options:
1. Sun exposure – it seems that we are meant to get most, if not all, of our vitamin D this way. However, due to spending time indoors, using sunscreen, having darker skin, living in high latitudes and living in polluted city areas, most of us do not. In Australia, luckily we do not live at the latitudes where vitamin D production from sunlight dwindles to zero in the winter. However, it does still fluctuate between seasons. And what’s more, when we are out in the heat of summer, we usually cover ourselves in sunscreen or wear long clothes to protect us from the sun. While this is definitely a good idea to protect from sunburn and heat stroke (and is absolutely necessary for fair-skinned people like me), it lessens the amount of vitamin D we can synthesise, during the season that we are meant to synthesise it. So we should consider…
2. Food sources of vitamin D – fish liver oils, oily fish (especially salmon, sardines and mackerel), beef liver, egg yolks and grass fed butter all contain vitamin D. It is also found in milk products and foods fortified with vitamin D. There are small amounts in plant sources such as mushrooms, dark leafy greens and alfalfa, however this is in the D2 form, and there is uncertainty as to how effective it is in the body. If trying to boost vitamin D levels, it is best to work on incorporating foods containing D3, which are the animal sources. However, it is difficult to get adequate amounts of vitamin D through food alone, which may lead you to look to…
3. Supplemental vitamin D – this is my preferred choice. The Adequate Intake amount for Australians has been set at 1000IU each day. The most effective way to take it is in the form of liquid emulsion drops, which are usually 400IU or 1000IU per drop. This means it is really easy to take, and also very potent, so make sure you check the dosage on the label! The vitamin D is emulsified in some kind of oil like coconut or sunflower, which is useful because since it is fat-soluble, it requires the presence of fat for absorption to occur. When reading labels, make sure to look for the D3 form (also known as cholecalciferol) which is the same form that our body makes and is therefore accustomed to using. It is usually derived from the lanolin in sheep’s wool, or less commonly from fish. For vegans, there is the option of taking D2 which is taken from mushrooms or lichen. However, this is a plant form which is not as easily recognised in the body, is roughly half as potent and does not appear to perform all of the same functions as the D3 form.
Supplementing with vitamin D is safe, easy and inexpensive, especially considering the wide array of ways it can benefit your health. However, taking excessive amounts may ironically cause a decrease in bone mass, so make sure to be careful when taking it, and it is best to take vitamin D together with vitamin K2.
It is important to remember that the immune system is very complex, and so there is no one measure that can make it work optimally. In addition to sufficient vitamin D, some other useful immune supplements include probiotics, mushrooms, zinc, vitamin C, vitamin A and herbs such as astragalus. However, as with many areas of our health, optimal immune function requires a diet rich in whole natural foods, adequate protein intake, lots of filtered water, regular exercise, plenty of sleep, a positive mental attitude and a relaxed state of mind.
This article is intended to provide information, not medical advice. Always speak to your professional healthcare provider before beginning a supplement program or attempting to treat a medical condition.
References
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Australian National Health and Medical Research Council, & New Zealand Ministry of Health (2014). Nutrient Reference Values for Australia and New Zealand: Vitamin D. Retrieved from https://www.nrv.gov.au/nutrients/vitamin-d
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