THE SUNSHINE VITAMIN
Why your body needs Vitamin D

The Basics of Vitamin D

Vitamin D is a fat-soluble vitamin that exists in two primary forms: D2 (ergocalciferol) and D3 (cholecalciferol). The two major sources of vitamin D are through sun exposure and dietary intake. This vitamin is essential for various bodily functions, including maintaining healthy bones, regulating the immune system, and aiding in calcium absorption.

Sunlight and Vitamin D Synthesis

Sunlight is the most natural and efficient way for our bodies to produce vitamin D. When ultraviolet B (UVB) rays from the sun interact with our skin, a chemical reaction occurs, converting a type of cholesterol into vitamin D3. This form of vitamin D is then transported to the liver and kidneys, where it is converted into its active form, calcitriol.

Several factors influence the synthesis of vitamin D through sunlight exposure, such as:

Geographic Location:
The intensity of UVB rays varies by location, with people living closer to the equator receiving more direct sunlight.

Time of Day:
The best time to synthesise vitamin D is when the sun is at its zenith, typically between 10am and 3pm.

Skin Type:
People with darker skin may require more sun exposure to produce the same amount of vitamin D as those with lighter skin.

Clothing and Sunscreen:
Wearing protective clothing or using sunscreen with a high sun protection factor (SPF) can reduce the skin's ability to produce vitamin D.

Dietary Sources of Vitamin D

While sunlight is a primary source of vitamin D, diet also plays a crucial role in ensuring adequate vitamin D intake. Some foods naturally contain vitamin D, including fatty fish (e.g., salmon, mackerel, and sardines), egg yolks, and beef liver.

Supplements for Vitamin D

In cases where individuals cannot get enough vitamin D from sunlight or diet, supplements may be recommended. Vitamin D supplements are available in both D2 and D3 forms and can be taken orally. They are commonly used to address deficiencies or as a preventive measure for those at risk of low vitamin D levels.

The recommended dietary allowance (RDA) for vitamin D varies depending on factors like age, gender, and life stage. It's important to consult with a healthcare professional to determine the appropriate dosage.

Factors Affecting Vitamin D Absorption

The body's ability to absorb vitamin D can be influenced by several factors, including:

Gut Health:
Proper functioning of the digestive system is essential for the absorption of fat-soluble vitamins like D.

Obesity:
Individuals with excess body fat may have lower bioavailability of vitamin D because it can get sequestered in fat tissue.

Age:
As we age, our skin becomes less efficient at producing vitamin D, and older adults may need more dietary or supplementary sources.