4 minute read
The importance of vitamin D
It’s safe to say that winter has well and truly arrived. The days are shorter, the nights are colder, and sunshine on our skin is warmly welcomed.
As we settle into the cooler months, our minds drift towards slow cooked dinners and meals prepared with warming spices. With less frequent exposure to sunlight, it’s also the time of year that we should consider our intake of vitamin D. Approximately one in four Australians are vitamin D deficient, with the likelihood of deficiency increasing during the winter period. As the risk of inadequate vitamin D affects all Australians, even those of us in the sunshine state, we need to be conscious of our intake, through both sunshine and dietary approaches.
Vitamin D is a fat-soluble vitamin, and it exists in two main forms. The first is cholecalciferol, which is the active form and known as D3, and is produced when our skin is exposed to UV rays from sunlight. The second is ergocalciferol, which is the inactive form and known as D2, and is the form that our body stores excess vitamin D as. When needed, D2 is converted in a multi-step process by the liver and kidneys back into D3. Because it is converted to its active form within specific organs and released to other parts of the body to carry out its functions, vitamin D is technically a hormone.
Vitamin D’s main role is to regulate the absorption of calcium and phosphorus at the small intestine to maintain balance in the body. When intake of calcium doesn’t meet the body’s needs, vitamin D will initiate a response to liberate calcium from the bone marrow to return the levels to normal. Vitamin D also plays a role in both our innate and our adaptive immune responses. This vitamin has an anti-inflammatory effect on many of our immune cells and because of this, vitamin D deficiency has been associated with an increased risk of developing autoimmune conditions, such as rheumatoid arthritis, and falling sick with infection.
Vitamin D is quite unique compared to other nutrients as the majority is supplied by the skin, rather than the diet. However, spending a lot of time in the sun doesn’t guarantee that you are converting vitamin D into its active form efficiently. Symptoms of deficiency include bone pain, muscle tenderness, and reduction in bone density. Before supplementing, it is important to know your vitamin D levels to avoid excessive intake. Excess vitamin D will increase the amount of calcium absorbed, causing hypercalcemia or high blood calcium levels. Vitamin D status is easily measured via blood test – or speak with one of our practitioners before beginning a supplement.
Sunlight provides the majority of the body’s vitamin D needs. For most adults, only a few minutes of midday sunshine per day is adequate. For Queenslanders, this is applicable year-round, however if you live in a cooler climate, aim for 2-3 hours of sunshine per week over winter. Meanwhile, dietary sources of vitamin D3 include animal-based foods such as egg yolk, oily fish such as salmon, and beef liver, while D2 is found in mushrooms. Placing your mushrooms in the midday sun will enhance the vitamin D2 content, with smaller mushrooms needing around 20 minutes and larger mushrooms needing around one hour. 100 grams of sunbaked mushrooms supplies the recommended intake for most adults.
When sun exposure and dietary intake are not sufficient, vitamin D supplementation may be appropriate. This is common during the colder months when our sun exposure decreases and our risk of falling ill increases. A high-quality vitamin D supplement will be in the active form, D3, and will provide 1000 IU per capsule. Speak with one of our practitioners in store to determine a dosage that is tailored to you. Vitamin D is best absorbed when taken alongside a meal containing a source of fat. This may mean taking your supplement alongside some avocado, oily fish, or nuts and seeds, all paired with some sunbaked mushrooms, of course!
