Vitamin D is essential for strong bones, muscles and general health and well-being. It’s known as the “sunshine vitamin” because our skin uses UV radiation from the sun to produce it. People who are deficient in vitamin D may have no symptoms at all, or they may be vague and hard to pinpoint. Here are a few warning signs to look out for.

1. A general unwell feeling

   For many people tiredness, subtle aches and pains and an overall feeling of being unwell are the only symptoms of a vitamin D deficiency.² If you aren’t feeling at your best, speak to your doctor about evaluating your vitamin D levels to rule out this as a possible cause.

2. Bone pain

   A vitamin D deficiency can weaken bones and make them more susceptible to hairline fractures. This can cause bones to feel painful when pressure is applied to them, due to tenderness and pain of the unnoticed fracture. Pain is often most obvious in the ribs and shin bones, although it can also occur in the thighs, feet, lower back, hips and pelvis.²

3. Muscle weakness

   Muscle weakness and pain may be a symptom of vitamin D deficiency in both children and adults.³ This is usually felt as a sensation of heaviness in the legs, tiring easily and difficulty in climbing stairs or getting up from a chair, for example.⁴

4. Blood test results

   A blood test provides the most accurate sign of vitamin D status. Your doctor will order a blood test called the 25‐hydroxy vitamin D test and you will need to have a sample of blood drawn. 25‐hydroxy vitamin D is converted in the kidneys to an active form of the vitamin that helps control levels of calcium and phosphate in the body. Different laboratories have slightly different normal value ranges, but in general the normal range is between 30 and 74 ng/ml. It is important to speak to your doctor about the meaning of your individual test results.⁵

If you suspect you might be at risk of developing a vitamin D deficiency you can also take the Ostelin Vitamin D Risk test.

The bones of the skeleton provide structural support for the body, allow for movement and protect our internal organs. Each bone is made from living tissue and is continuously being rebuilt throughout life. This includes the removal of old, damaged bone tissue and its replacement with new, stronger bone.¹ So, if bone is constantly being remade, what are the factors involved in making them strong and healthy?

Bone reacts to mechanical stress (weight bearing movement) by changing size and shape. Bone tissue is added in areas of high mechanical stress, which increases the strength of bone and therefore its resistance to fractures.² This is why exercise is such an important part of maintaining healthy, strong bones. Weight bearing exercises such as walking, jogging, dancing, and muscle strength training such as lifting weights, place mechanical stress on the bones, causing them to become stronger. During childhood and adolescence, exercise helps build up maximum bone strength. In adulthood, it promotes the maintenance of muscle and bone strength and in older adults it reduces bone loss.³

A healthy well‐balanced diet is also needed. The amount of minerals such as calcium and phosphorous⁴ found in bone is another important factor in their strength. Other nutrients that play important roles in supporting bone health include vitamin D, vitamin K, boron, magnesium and manganese.

In addition to nutritional status and exercise levels, the degree of bone mineralisation in an individual also depends on hormonal factors and age. As we age, our bones tend to lose mass, making them more likely to fracture. Women tend to have a lower bone mineral content than men and this gap widens with aging. Women also tend to lose more bone mass after menopause, due to a lack of oestrogen.⁵ Reaching maximum bone density during our adolescence and maintaining it during adulthood is beneficial in our later years when some bone loss is inevitable.

Vitamin D is essential to bone health, playing an important role in protecting bone tissue and also helping to absorb calcium. During childhood, you need vitamin D to build strong bones and in adulthood, you need it to maintain them.

Who is at risk of a vitamin D deficiency?

Your risk of becoming deficient in vitamin D increases with age, especially in women. In fact, 57 percent of women over the age of 75 years in Australia have been found to be deficient. This is particularly important, as vitamin D deficiency is a key risk factor for falls and fractures in the elderly.¹ Other risk factors include those with little to no sun exposure, such as hospitalized people, those in aged care or housebound individuals, women who are pregnant and those who wear clothes that cover the whole body for religious or cultural reasons.²

How do we get vitamin D?

Our body gets vitamin D in three ways: from sunlight, the food we eat and from dietary supplements. Your skin produces vitamin D when exposed to ultraviolet B (UVB) rays in sunlight. However, due to health concerns surrounding sun exposure, such as premature ageing and skin cancer, many people avoid sunlight by staying indoors or wearing protective clothing. Increased awareness of the risks of skin cancer from sun exposure means that despite our largely sunny climate, vitamin D deficiency has become a significant public health concern, with an estimated 31% of adults in Australia having inadequate vitamin D levels.⁴

A decrease in sun exposure has led to a need for more vitamin D to be taken in through our diet. This can be difficult to achieve, as there are only small amounts of vitamin D in some foods, for example fish and eggs. Certain food products, such as some brands of milk and margarine have added vitamin D. However, most people only get around five to ten percent of their daily vitamin D from foods. If you are found to have low levels of vitamin D, a supplement in the form of drops, capsules or tablets may be recommended by your doctor. These are a convenient, cost effective way to ensure you are getting enough vitamin D every day.²

How can I find out if I am deficient?

If you are concerned that you may be vitamin D deficient in vitamin D, speak to your doctor. They will be able to perform a simple blood test to check your vitamin D status and assess your risk factors. If you are found to be sufficient, they may prescribe a vitamin D supplement to help increase your vitamin D levels.²