4 Things You Need to Know About Vitamin D

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Vitamin D, aka “the sunshine vitamin,” is one of the most essential of vitamins.This super vitamin is responsible for healthy bones. It facilitates the absorption of calcium into bone tissue. Therefore, vitamin D deficiency is often responsible for weak bones. In children, it can lead to a condition known as rickets, where bones become fragile and malformed due to it’s poor mineralization. In adults, poor calcium absorption leads to osteoporosis. Research also shows that vitamin D deficiency puts you at higher risk for developing chronic illnesses including autoimmune diseases, cardiovascular problems, diabetes, and even cancer. Furthermore, researchers attribute vitamin D deficiency to sleep apnea (read article until the end).

Where does vitamin D come from?

There are two main sources of vitamin D. By far, the primary source of vitamin D is our own skin. This mechanism one of the many functions of skin as an organ system. The body is able to synthesize vitamin D through direct exposure to sunlight. The skin utilizes UVB rays from the sun to transform a precursor molecule (7-dehydrocholesterol) into vitamin D3.  It then travels to the kidneys to help reabsorb calcium into the bloodstream for redistribution. That is why daily intake of sunlight and a balanced diet are essential for keeping health bones.

A secondary source of vitamin D is food. For the most part, you may find vitamin D in some fish species. Sardines, Salmon, Mackerel, and Tuna are excellent sources of vitamin D. In addition, you may eat some foods fortified with vitamin D. Examples include, eggs, raw milk, caviar, and mushrooms. Beyond food, you may take vitamin D supplements. Should you suspect vitamin D deficiency, it’s best recommended that you consult your primary care physician before taking supplements. Vitamin D levels should be monitored by a qualified physician.

Causes of Vitamin D Deficiency

Research shows that about 1 billion people worldwide are vitamin D deficient (1). People most prone to a vitamin D deficiency include those who don’t spend enough time outdoors, those who live in areas with poor exposure to sunlight (northern and southern hemispheres), and in people with darker skin or those who wear multiple layers of clothing. Furthermore, you may become deficient if over time you don’t consume the recommended levels. This is especially true for those who keep a low fat diet, those who don’t eat fish, egg yolks, and drink fortified milk.

Vitamin D Affects Our Appetite and How Our Bodies Store Fat

During the summertime, the average person living in the US receives higher doses of sunlight. Therefore, our bodies contain a surplus supply of vitamin D. Researchers suggest that our bodies interpret the surplus of vitamin D as an opportunity to grow muscle and build stronger bodies. As a result, we eat more calories and store less fat. During the wintertime, as the earth tilts on it axis the amount of UVB rays decreases. Consequently, our bodies sleep longer, use less energy, and store fat to get ready for spring. Just like weather apps on smartphones can help us decide what to wear before leaving the house, sunlight “informs” our bodies how to manage our energy supply throughout the day.

Vitamin D Deficiency Has Negative Effects On Sleep

Researchers have concluded that vitamin D may also play a role in sleep. Low vitamin D increases the risk of insufficient sleep (less than 5 hrs a night) and scoring below 70% on the healthy sleep efficiency score. Healthy sleep efficiency is generally considered to be 85% or above. Low scores indicate that sleep may be fragmented and restless, with multiple awakenings throughout the night. Other studies also suggest that people who suffer from sleep apnea may also be vitamin D deficient (2). This is an area of research with a lot of potential. Additional studies to help us understand the relationship between this super vitamin and sleep is forthcoming. Should you suspect to have a sleep disorder, ask your primary care physician to evaluate your risk and get tested if necessary.

  1. F. Holick, Michael. Vitamin D: Evolutionary, Physiological and Health Perspectives. Current Drug Targets, vol. 12, No. 1, January 2011, pp.4-18. (Accessed online on June 20, 2017: http://www.ingentaconnect.com/content/ben/cdt/2011/00000012/00000001/art00002).
  2. Breus, Michael. “Low On Vitamin D, Sleep Suffers.” In Health, How to Sleep Better, February 26, 2016. Accessed online on 6/30/17 (https://www.thesleepdoctor.com/2016/02/26/low-on-vitamin-d-sleep-suffers).