Vitamin D deficiency is common in Australia. It is estimated that over 30% of Australians have mild, moderate or severe vitamin D deficiency. Vitamin D facilitates calcium absorption from the gut and helps to maintain normal calcium concentrations in the body. This is important for bone and muscle health. Vitamin D also plays many other roles in the body such as reducing inflammation and modulation of immune function.
The main source of vitamin D in Australia is from sunlight exposure. There is small amounts of vitamin D found in foods such as liver, oily fish and egg yolks, however, dietary sources are generally unable to provide adequate amounts of vitamin D. Oftentimes, supplementation is required for a person to maintain normal vitamin D levels.
Seasonally, Vitamin D levels will vary. It is recommended that blood levels of Vitamin D are >50nmol/L at the end of Winter, and around 60-70nmol/L at the end of Summer. People who carry excess adipose tissue (fat cells) are more at risk of Vitamin D deficiency as the fat cells store Vitamin D which can lead to lower serum (blood) levels.
Depending on the level of deficiency, your Doctor may recommend anywhere between 1,000IU-5,000IU vitamin D supplement per day until the body is replete. You may also be recommended to continue a maintenance dose of 1,000-2,000IU per day depending on your circumstances.