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What is Vitamin D? Why is it Important?

Out of all the vitamins, Vitamin D may be the most recognizable and well-known out of the bunch. As children, we learned that Vitamin D helped make our teeth and bones strong, and as we enter adulthood, that sentiment remains engrained in the back of our heads. But what exactly is Vitamin D?

It turns out that Vitamin D is one of the oldest hormones that has existed in our world for over 500 million years[1]. Lifeforms such as phytoplankton and zooplankton are recorded to have produced Vitamin D when exposed to sunlight. Vitamin D is an integrative part of healthy skeletal growth and development, and is a contributing factor to why these oceanic organisms were able to eventually venture on to land and continue the evolution of lifeforms.

While Vitamin D has always been closely associated with dairy products, specifically milk, it is most prominent in solar ultraviolet radiation. American endocrinologist and specialist of Vitamin D, Michael F. Holick, refers to Vitamin D as “the sunshine vitamin”. This is because the best form of intaking Vitamin D is by basking in sunlight. According to Holick, 90-100% of Vitamin D requirements in humans comes directly from sunlight[2]. Cave paintings from some of the earliest human life depict an immense appreciate for sunlight, not only for its warmth, but also the life-giving properties it provides.

Not only is Vitamin D important because it allowed us to continue the process of evolution, but the consequences and effects of a Vitamin D deficiency can have major impacts on a person. In children, Vitamin D deficiency can lead to Rickets, a condition that can cause weak bone development that may progress into pain and deformities. This was extremely evident during the Industrial Revolution, when children were inside factories all day and the air pollution obstructed sunlight, leading to an epidemic of Vitamin D deficiencies. In adults, a Vitamin D deficiency can prompt Osteomalacia, the softening of bones, and Osteoporosis, the thinning and weakening of bones.

Overtime, Vitamin D has become a necessary hormone that contributes to the overall health and wellness in a person. Vitamin D has shown to not only play a significant role in skeletal health, but other organs as well, such as the brain, heart, stomach, and pancreas. Holick argues that the surveillance of Vitamin D within humans should be part of normal yearly examinations due to its importance, “There needs to be a better appreciation of the importance of Vitamin D for overall health and well being”[3].

[1] Holick, M. F. (2004, December 1). Sunlight and Vitamin D for bone health and preventions of autoimmune diseases, cancers, and cardiovascular disease. Oxford Academic. [2] Holick, M. F. (2003, February 1). Vitamin D: A millennium perspective. Wiley Online Library. [3] Holick, M. F. (2003, February 1). Vitamin D: A millennium perspective. Wiley Online Library.


Blog Contributors

Author- Sophia Galvez

Editor- Kaitlyn Longstaff

Public Health Scientist- LaCher E-W, MPH


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