Vitamin D Benefits: Bone Health, Immunity & Supplements | CellTriagen

Introduction

Vitamin D is a fat-soluble vitamin that comes in two forms: ergocalciferol (D2) and cholecalciferol (D3). Vitamin D helps regulate calcium and phosphorus, which help maintain healthy bones and teeth. It also supports the immune system, brain health, and healthy muscle function.

Vitamin D deficiency

Severe vitamin D deficiency occurs when serum 25(OH)D concentration levels are less than 25.0 or 30.0 nmol per litre (there is some disagreement about the exact diagnostic thresholds for vitamin D deficiency and insufficiency). Vitamin D insufficiency is typically classified when serum 25(OH)D levels sit between 25.0 or 30.0 and 49.9 nmol per litre. Vitamin D levels vary worldwide. However, lack of vitamin D intake is a concerning problem. For example, an estimated 40% of Europe's population has insufficient vitamin D levels, followed by 37% of Canada, 24% of the USA, and nearly 25% of Australia.

Causes of vitamin D deficiency

Lack of skin exposure to sunlight is a significant contributor to insufficient vitamin D. Some medications interfere with the absorption of vitamin D in the body. This includes some steroids, cholesterol-lowering medicine, laxatives, or orlistat (a lipase inhibitor for weight loss, marketed as Xenical). Both obesity and weight-loss surgery can also result in lower absorption rates of vitamin D. Chronic diseases such as celiac disease or Crohn's disease are another cause of vitamin D deficiency. The ageing process also reduces the absorption rates of vitamin D, particularly for those aged over 65.

Health outcomes of vitamin D deficiency

Bone health is dependent on sufficient levels of calcium. However, the body relies upon Vitamin D to effectively absorb calcium through the large intestine (colon). Vitamin D deficiency can also increase our susceptibility to acute infections and chronic diseases like cardiovascular disease and certain cancers.

Sources of vitamin D

The primary source of vitamin D is sunlight, which provides up to 80% of our vitamin D supply. The skin synthesises vitamin D when exposed to ultraviolet rays from the sun. However, some parts of the world may experience insufficient access to sunlight, for example, during the winter months when there are few hours of sunlight each day. Small amounts of vitamin D can be accessed from some foods. Another option is taking a vitamin D supplement, available as vitamin D2 (ergocalciferol) and D3 (cholecalciferol). D3 is more effective at raising blood levels of vitamin D.

Foods containing vitamin D

We can naturally supplement our vitamin D intake with certain foods. Fatty fish (i.e., tuna, salmon, sardines), mushrooms, egg yolks, and cod liver oil all contain natural amounts of vitamin D. Another source of vitamin D comes from eating foods fortified with this vitamin. For example, in some countries, common foods have vitamin D added during the production process. Look for evidence of this fortification on the labels of milk, yogurt, margarine, cereal, and bread products.

Health benefits of vitamin D

Research shows that maintaining adequate levels of vitamin D promotes healthy bones, prevents fractures, and supports the body's immunity. It may reduce the risk of some chronic diseases. Without testing, vitamin D deficiency may go unnoticed for a time. Therefore, it is a good idea to consult your healthcare professional and get a blood test before starting any vitamin D supplements. Be sure to discuss with your healthcare professional whether vitamin D supplements can enhance your health alongside a nutritious diet and appropriate time spent in the sunshine each day.