I have previously talked about Vitamin D in relation to immune health, which you can check out that blog here Immune boosting tips to avoid the flu. But this Vitamin is needed for so many other reactions within the body. Vitamin D is a fat soluble nutrient (meaning it needs fat to be absorbed), made up of several forms which are cholesterol like substances. Vitamin D3 is the form found in animal products and D2 is a form sometimes found in supplements and fortified foods.
The body has the ability to produce D3 by converting a cholesterol based precursor in the skin when exposed to sunlight. This conversion occurs over a 2-3 day period and studies have shown that short periods of sun exposure are more beneficial than long periods. Australian recommendations for healthy sun exposure depend on locality and skin type. For example someone with fair skin living in Melbourne needs about 15 minutes of sun on 15% of their body everyday, this time increases to about 30 minutes in cooler weather. Someone with darker skin may need 3 to 6 times more exposure due to the difference of pigmentation in the skin.
It is estimated that up to 58% of Australians are Vitamin D deficient, you can read about that here, and its easy to see why. For those of us who work in a 9-5 job indoors, seeing any sunlight particularly in winter can be a challenge. Many of us leave for work and get home in the dark, and lets face it getting outside on our lunch break when its 15 degrees is less than appealing. Combine this with successful campaigns telling us to avoid and cover up from the sun it is any wonder the rate of deficiency is not higher.
The National Health and Medical Research Council reports that it is almost impossible to obtain the required amounts of Vitamin D through diet alone, particularly when levels in animal products are declining through modern day farming practises. Some brands of eggs, milk and margarine are fortified with vitamin D. However these products cannot be relied on to help boost Vitamin D levels. Vitamin D2 is the form used in food fortification. Studies have shown that Vitamin D2 can actually cause a decline in Vitamin D3 which is the active form the body uses for many purposes in the body, you can read more about this here.
The discovery of Vitamin D Receptors (VDR) on a diverse number of cells in the body has caused a shift in the known functions of Vitamin D in recent times. Traditionally associated with bone health, the discovery of VDRs on cells and tissue of the brain, skeletal and vascular smooth muscle, breast, prostate and immune cells indicates its use goes far beyond strong bones.
Vitamin D is required to maintain strength and function of various muscles within the body, including skeletal and those in the cardiovascular, respiratory and reproductive systems. Muscles are more than just biceps, triceps or gluteus maximus and there are some pretty important systems that are affected. The heart is an organ made up of muscle, and Vitamin D has been shown to have a direct effect by improving its function of pumping oxygenated blood out into the body.
In the brain, Vitamin D is required in the production of some neurotransmitters such as serotonin and has neuroprotective effects. Deficiency has been linked to developmental psychiatric disorders such as autism, schizophrenia and Parkinson disease.
Vitamin D is also key in maintaining the correct balance of calcium and phosphorus in the blood. If the body senses that these minerals are out of balance it will initiate a sequence of reactions to enhance dietary calcium and/or phosphorus absorption through the release of Vitamin D. The Vitamin D improves the absorption from the small intestine and helps to maintain the crucial balance between these two minerals to maintain bone health. Bones also require Vitamin K as it is this nutrient that sets the calcium in the bone to give them strength.
Maintaining a balance between calcium and phosphorus is vital in the prevention of some diseases. Problems can occur if dietary intake of phosphorus is greater than that of calcium. Phosphorus is particularly high in processed food and soft drink. If you drink a lot of soft drink but don’t get sufficient calcium from sources such as fish, nuts and leafy green veg you may be setting yourself up for long term health complications such as osteoporosis or cardiovascular disease. The importance of Vitamin D in this equation is it must be available (along with calcium) to restore balance.
Vitamin D has also been shown to influence a number of conditions such as periodontal disease, multiple sclerosis, macular degeneration, dementia and migraines. Deficiency is associated with a higher risk of falls in the elderly.
So how can you increase your intake of Vitamin D? Again it all comes down to the fact that this is a daily requirement and you need to be mindful of how you will fit it into your day. Being sun smart is important but you also need to know that sunscreen blocks the UVB rays which are needed to make Vitamin D. Now I am not telling you to go out in blistering sun unprotected, but during the cooler months you will be safe to be exposed for up to 30 minutes. In summer the time needed in the sun decreases to just 15 minutes in Melbourne because the rays are stronger.
But what if you just cant get out in the sun enough? Cod liver oil is an excellent source of Vitamin D, but it can be hard for some to people take due to its taste. Fortunately Vitamin D is available in supplement form, with a whole range of different brands available. Choosing the right one can be confusing as not all supplements are created equally. Always speak to a professional to ensure you are making a good choice.
However you choose to get your Vitamin D, I hope that through reading this you have a better understanding of why this nutrient, along with all the others is so important. Understanding how to get these nutrients is just as crucial, and some consideration needs to be made to ensure you are not missing out. It starts by just making one small change, that potentially can be the one your well being depends on.
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Belinda Bird 