Deficits in vitamin D3 (cholecalciferol) have been linked with an increased risk of cancer and other diseases; yet its dynamic effects often go overlooked.

Maintaining population vitamin D sufficiency reduces chronic disease burden and sepsis, lowers COVID-19-related hospitalizations/deaths/healthcare costs and is key to meeting COVID-19 targets. A multifaceted approach should be taken in achieving this objective.

Vitamin D Deficiency

Vitamin D deficiency can impede your body’s ability to absorb and utilize calcium, leading to bone health issues and even contributing to cardiovascular disease, depression, diabetes and multiple sclerosis – making effective diagnosis and treatment from multiprofessional teams of vitamin D deficiency all the more crucial.

Vitamin D deficiency affects many individuals. Older adults are especially vulnerable as their ability to synthesize vitamin D decreases with age and they spend more time indoors; those with darker skin are at increased risk due to melanin pigment acting like natural sunscreen, reducing subcutaneous vitamin D synthesis. Others who don’t spend enough time outdoors due to work, illness or a lack of outdoor space in their neighborhoods also run the risk of vitamin D deficiency; those who cover themselves for cultural or religious reasons also face reduced chances of receiving sufficient sunlight needed to create vitamin D production.

The vitamin D blood test measures levels of 25-hydroxy vitamin D (25(OH)D). It can be performed easily at home using a simple blood sample and serves as an affordable way to evaluate overall cardiovascular disease risk and track treatment efficacy. A normal range for this measurement lies between 20-40 ng/mL.

Lack of vitamin D intake can result in osteomalacia or rickets, conditions which cause soft bones. Osteomalacia affects adults as well as children, often causing pain, brittle or curved bones, short stature, or short stature; Rickets is a childhood disease which results in soft bones bending legs abnormally.

Vitamin D is fat soluble, so its absorption depends on a person’s gut’s ability to process dietary fat efficiently; therefore, those suffering from medical conditions that impair this process such as cystic fibrosis, Crohn’s disease, celiac disease liver disease or some forms of obesity may be at increased risk of vitamin D deficiency. Insufficient consumption of fatty foods may also contribute to vitamin D deficiency.

Sun Exposure

Most people worldwide fulfill all or most of their vitamin D requirements through sunlight exposure [1]. Sunlight with wavelengths between 290-320 nanometers penetrates exposed skin, where it converts 7-dehydrocholesterol to previtamin D3, before producing vitamin D3. Season, time of day, cloud cover, smog levels and body melanin content all affect how much UVB radiation reaches our bodies’ surfaces. Sunscreen can also inhibit vitamin D synthesis by blocking UVB rays from reaching the skin and reaching their destination. Most researchers still believe it’s possible for individuals living in sunny regions or regularly exposing large portions of their bodies (for instance, wearing a hat and long-sleeved shirt while working outdoors) to sunlight to produce sufficient vitamin D levels.

Concerns over skin cancer risk have caused people to spend less time outdoors, which may contribute to widespread vitamin D deficiency. Unfortunately, most research conducted on sun exposure and vitamin D cannot establish direct cause-and-effect relationships – only well-designed randomized clinical trials can establish such connections.

Vitamin D is an essential nutrient, essential for bone strength. It promotes immune health, controls inflammation and modulates cell growth – as well as being found in foods like fatty fish, egg yolks and dairy products – with deficiencies leading to bone disease rickets in children and as potential risk factors for multiple sclerosis risk factors. Also referred to as cholecalciferol.

Just 15 minutes of sunbathing once or twice weekly should be sufficient to provide adequate vitamin D levels; otherwise it’s difficult to ensure adequate levels are obtained through diet alone as sources are typically limited.

Vitamin D Supplements

Vitamin D is a group of fat-soluble secosteroids essential for increasing intestinal absorption of calcium, magnesium and phosphate, as well as other biological functions, including bone health. Our bodies naturally synthesize vitamin D through exposure to sunlight; however, sun-induced vitamin D production varies depending on season, time of day, latitude and skin pigmentation as well as sunscreen use which limits production.

Supplementing diet with vitamin D has been demonstrated to raise serum concentrations of 25(OH)D – the biologically active form of vitamin D – by nearly 40 percent, according to research published by the Institute of Medicine (IOM). They recently recommended that adults consume 600 IU (2000 g) daily in order to reach and maintain adequate blood levels of 25(OH)D.

Vitamin D stands apart from other vitamins in its biological activity is controlled by two hydroxylation reactions occurring in both liver and kidney to produce physiologically active 1,25-dihydroxyvitamin D (2,25(OH)2D), or calcitriol. According to IOM recommendations circulating levels of 2,25(OH)2D should serve as the main indicator of vitamin D status.

People with low levels of 25(OH)D who took 2,000 IU daily of vitamin D for four months experienced an average increase in serum levels to over 70nmol/L (28ng/ml), though no significant changes occurred to lower-extremity power or strength. [2]

Foods high in vitamin D include salmon, tuna, sardines, butter, egg yolks and fortified dairy products such as yogurt. One tablespoon of cod liver oil provides 1,360 IU, with oral vitamin D supplements also being available. Those who are having difficulty digesting fat due to malabsorption disorders such as Crohn’s disease, celiac disease or inflammatory bowel disease are at an increased risk for vitamin D deficiency due to not being able to absorb its presence – they may require vitamin D supplementation in such cases. [4]This page was last updated on 11/20/2020

Vitamin D Rich Foods

Vitamin D obtained through sunlight or food must undergo two hydroxylation processes in the body in order to become biologically active. One takes place in the liver and produces 25-hydroxyvitamin D [25(OH)D], also referred to as calcidiol. Meanwhile, kidneys convert 25(OH)D into 1,25(OH)2D commonly known as calcitriol – both are physiologically active forms of vitamin D that must undergo further processing for its biological benefits.

Fatty fish such as salmon, tuna and mackerel are excellent sources of vitamin D, while milk and egg yolks also contain small amounts of this nutrient. Fortified foods also provide significant sources of this essential nutrient, and human studies have confirmed its most studied form – vitamin D2 found mostly in mushrooms which can also be purchased as supplements.

Vitamin D deficiency is a global issue and most populations worldwide. People who do not spend much time outdoors, particularly those in northern climates, are at increased risk of deficiency. People with darker skin tones produce less vitamin D from sun exposure compared to those with lighter skin tones and their ability to synthesize vitamin D decreases with age due to factors like reduced 7-dehydrocholesterol production, skin changes, increased use of sunscreen or spending more time indoors.

Some medical conditions may restrict an individual’s vitamin D intake, including fat malabsorption caused by liver diseases (e.g., nonalcoholic fatty liver disease), celiac disease, Crohn’s disease and ulcerative colitis. These may also interfere with absorption from food sources containing fortified vitamins such as cereal.

The vitamin D Advisory Committee that established RDIs found that daily vitamin D intake below 250 mcg (10 000 IU) would unlikely cause adverse signs and symptoms; however, lower levels may eventually be linked to adverse health outcomes such as decreased resistance to infection and fracture risk – both potential issues associated with hip and spine osteoporosis. Unfortunately, due to no direct relationship between blood serum levels of vitamin D and other health outcomes.