Vitamin D, often referred to as the Sunshine Vitamin, plays a crucial role in numerous bodily processes ranging from calcium absorption and immune regulation, mood regulation and fatigue relief.

Vitamin D can be obtained through various food sources, including fatty fish and egg yolks; or fortified products like milk, orange juice or cereal. Supplements may also be available.

What is Vitamin D?

Vitamin D is a fat-soluble vitamin with multiple functions. It plays an integral part in maintaining strong bones and supporting immune function. People can obtain Vitamin D through sunlight exposure, specific foods and dietary supplements; and its production by ultraviolet (UV) radiation from sunlight striking skin and stimulating vitamin synthesis. Although not classified as hormone, Vitamin D plays an integral part in modulating inflammation response mechanisms.

Sunlight is the primary source of vitamin D for most people, yet not everyone receives enough. People who spend most of their time indoors – like office workers or those driving in cars – may produce less vitamin D; those with darker skin require additional sun exposure in order to produce equal amounts. Sunscreen may also decrease vitamin D synthesis.

Body absorption of vitamin D is limited; too much and toxicities can result. Vitamin D toxicity typically arises from taking high doses of oral supplements; rarely will such levels reach toxic levels through natural sources like food or sunshine.

Vitamin D supplements may improve health outcomes, yet evidence is often conflicted. Blood levels of serum 25-hydroxyvitamin D or 25(OH)D serve as the main indicator of someone’s vitamin D status; their level can be reported either as nanomoles per liter (nmol/L) or nanograms per milliliter (ng/mL).

Vitamin D obtained through diet or supplement is biologically inert and must undergo two hydroxylation processes to become biologically active vitamin D [1,2]. The initial hydroxylation takes place in the liver; subsequent hydroxylations occur in both kidneys to produce 1,25-dihydroxyvitamin D [1,25(OH)2D], also known as calcitriol. Once active vitamin D reaches serum concentrations it increases proportionally with intakes [3,4]. Unfortunately, however, according to FNB Vitamin D RRIs there was insufficient evidence available supporting any correlations between vitamin D intakes and any health outcomes other than bone health [1,2, 5].

Why is Vitamin D Important?

Vitamin D, also known as the “sunshine vitamin,” plays an essential role in calcium absorption for bone development and remodeling (the process by which old tissue is removed and new bone formed), as well as protecting against osteoporosis, a disease in which density and strength decrease over time. Without it, bones would be thin and fragile without this essential mineral nutrient. Additionally, Vitamin D also protects against osteoporosis–an age-related decline of bone strength which occurs over time – by keeping cells happy through stimulation of receptors on receptors on nerve endings along nerve fibers – another essential nutrient necessary for bone health! Vitamin D also protects against osteoporosis– a disease which involves density decrease over time as bone strength decreases due to decreased calcium absorption via receptors on nerve endings on bones preventing loss due to calcium absorption by protecting receptors on nerve endings on receptors on receptors on receptors on receptors located on receptors on receptors on cell surface areas where bone tissue replaces new bone forms from within tissues by taking calcium into cells forming new bone cell from an area. Without Vitamin D’s protection from osteoporosis– preventing density reduction that leads to disease of which bone density decreases with strength resulting in the spine due to bone strength loss over time as the protective factor from its anti-bone protection from being present.

Vitamin D deficiency in children or osteomalacia in adults may lead to rickets and osteomalacia – conditions in which bones become soft, weak and misshapen; osteomalacia causes bone pain and muscle weakness.

At-risk groups for vitamin D deficiency include those who receive limited exposure to sunlight, those who wear clothes and hats which block sunlight from reaching the skin, individuals with dark skin pigmentation and those taking certain medications or supplements. Obesity also has an adverse impact on vitamin D levels due to excess body fat sequestering it and decreasing serum 25(OH)D concentrations.

Vitamin D can be found naturally in many foods and in certain supplements; however, sun exposure remains the best way to receive adequate amounts. People unable to go outside safely, such as elderly persons living in nursing homes and infants in childcare facilities, may take vitamin D containing supplements; however it’s important to remember that too much Vitamin D could be harmful.

Studies of Vitamin D’s effects have not produced definitive answers, although evidence indicates it plays an essential role in supporting immune functioning and may help lower risks associated with chronic illnesses like cancer, heart disease and diabetes. More research needs to be conducted before conclusive claims can be made; more specifically the committee responsible for creating Recommended Dietary Intakes for Vitamin D found that evidence was insufficient to establish a link between Vitamin D intake and many health outcomes including immunity against infection as well as overall functioning of immunity; other research indicates a lower risk for COVID-19 infections than Vitamin D was associated with.

How do I get Vitamin D?

Under normal conditions, most adults can obtain all of their vitamin D needs through sunlight exposure on their skin and eating healthily between late March/early April and September. We no longer produce vitamin D during autumn and winter when sunlight levels decline significantly; those at risk, including people with dark skin or who may require long-term supplementation due to genetics may need to take Vitamin D supplements throughout the year; children under five years are at heightened risk and can get free supplements through their GP or Healthy Start provider.

There are various natural and fortified sources of Vitamin D available. An FNB committee determines an RDA, measured in micrograms per International Unit (1 microgram = 40 IU). A RDA of 50nmol/L (20ng/mL) 25(OH)D should provide enough vitamin D to support bone health and calcium metabolism.

Remember that vitamin D from sunlight, food or dietary supplements must go through two hydroxylation processes in your body in order to become biologically active – only then can it support bone health and immunity.

Once these reactions have taken place, 1,25-dihydroxyvitamin D [1,25(OH)2D], more commonly referred to as calcitriol, is formed. This form of vitamin D helps regulate blood calcium levels, promote bone growth and prevent rickets in children as well as osteomalacia in adults.

There are various factors that may contribute to low levels of Vitamin D in the blood, including exposure to too little sunlight, ageing with darker skin tone and digestive conditions such as Crohn’s or celiac disease which impede absorption of fat-soluble vitamins. Common signs of vitamin D deficiency include aching bones and muscles. It may also result in weak and soft teeth as well as lead to scurvy.

What is the best way to get Vitamin D?

There are three factors that determine how much vitamin D your body can make: 1) your skin tone (darker skin requires more sun than lighter skin to produce adequate levels); 2) age (as we age, our ability to produce vitamin D decreases); and 3) geography (being closer to the equator increases exposure and therefore creates more vitamin D production).

Vitamin D can best be obtained through sunlight. Most people with light skin need only 20 to 30 minutes of direct sun three times each week in unprotected sun for reaching their daily vitamin D requirements (remembering to use sunscreen on exposed areas in order to avoid skin damage or cancer).

Food can be an excellent source of vitamin D. Certain foods naturally contain small amounts, like fatty fish and eggs; others such as milk, soy drinks, orange juice and breakfast cereals may contain added quantities – be sure to read nutrition labels when shopping!

If your body cannot obtain sufficient vitamin D from sunlight or your doctor has identified that you have a deficiency, taking daily vitamin D supplements is often advised. They come in liquid, capsule and tablet formats and should be taken either with food or alone; it is suggested taking one with meals that contain fat as this aids absorption.

Attaining enough vitamin D is key for supporting healthy bones and muscles. If you’re finding it hard to meet your vitamin D requirements through diet alone, talk with your GP or pharmacist about supplementation – women and children eligible for Australia’s Healthy Start scheme can receive free vitamins D supplements from pharmacies or supermarkets in Australia. Low vitamin D levels can have serious repercussions for bone strength, muscle function, immunity as well as mood and mental wellbeing – the best way to ensure sufficient amounts are coming in through sunlight exposure combined with healthy eating plans.