Is Your Sunscreen Harming Your Health?

Kea Schwarz
By: Kea Schwartz 

Vitamin D is a fat-soluble vitamin that is naturally present in certain foods while other foods are fortified with vitamin D. Dietary supplements are also available, but the most naturally occurring way to retain vitamin D is through direct skin exposure to sunlight. Regardless all forms are biologically inert until they process through two hydroxylations for activation in the body. 1

Vitamin D aids in calcium absorption in the gut and helps to balance concentrations of calcium and phosphate to maintain proper mineralization of bones and to prevent hypocalcemic tetany. It is also vital in bone growth and remodeling. In the absence of Vitamin D, bones can become brittle, or misshapen. In severe cases, it can cause rickets in children, osteomalacia and osteoporosis in adults. In addition, vitamin D is important for cell growth, neuromuscular function, immune function, reducing inflammation, and cell proliferation and differentiation.1

There aren’t many natural food sources containing vitamin D. Most foods are fortified and provide the most common sources of vitamin D in the American diet. A few of the dietary sources include fatty fish like salmon and tuna. Also, egg yolks, portabella mushroom, beef liver, cheese, and fish liver oils, fortified milks and breakfast cereals are all good sources of vitamin D.2

Most people meet some of their vitamin D needs through exposure to sunlight. Many factors including season, geographic region time of day, cloud cover, air pollution and skin pigmentation (lighter skin synthesizes more vitamin D than darker skin, and sunscreen) can impact the amount of UV radiation exposure and vitamin D synthesis. Additionally, as researchers suggest, 5- 30 minutes of sun expose between 10 AM and 3 PM, at least twice a week to the face, arms, legs, or back void of sunscreen will usually promote sufficient synthesis of vitamin D.  It is important to skip sunscreen during these sessions because application of sunscreen with SPF 15 or greater has been shown to decrease vitamin D production by 99 percent.3 Individuals with minimal access to sun exposure may require a supplement to achieve recommended levels of intake. The recommended intake levels are presented in the chart below taken from the National Institute of Health Vitamin D fact sheet on their website.1

 

Recommended Dietary Allowances (RDAs) for Vitamin D [1]
Age Male Female Pregnancy Lactation

0–12 months*

400 IU
(10 mcg)
400 IU
(10 mcg)
   
1–13 years 600 IU
(15 mcg)
600 IU
(15 mcg)
   
14–18 years 600 IU
(15 mcg)
600 IU
(15 mcg)
600 IU
(15 mcg)
600 IU
(15 mcg)
19–50 years 600 IU
(15 mcg)
600 IU
(15 mcg)
600 IU
(15 mcg)
600 IU
(15 mcg)
51–70 years 600 IU
(15 mcg)
600 IU
(15 mcg)
   
>70 years 800 IU
(20 mcg)
800 IU
(20 mcg)
   

* Adequate Intake (AI)

There are many risk factors associated with deficiency in vitamin D absorption, including inadequate dietary sources, malabsorption, and inadequate sunlight exposure related to over use of sunscreens.  Symptoms that arise due to lack of vitamin D include muscle weakness and bone fractures. Also, certain diseases that can arise from deficiency include type 2 diabetes, crohn’s disease, and celiac disease. Ongoing research is determining if vitamin D deficiency plays a role in multiple sclerosis, autoimmune disorders, respiratory disease, cancers, cardiometabolic disease, and infections.3

Overall, people are spending more time indoors and when they go outdoors they generally apply sunscreen which inhibits the body’s ability to produce vitamin D. Although it is important to protect yourself against skin cancer it is also necessary to receive moderate levels of exposure to sunlight to help boost vitamin D synthesis.


References:

  1. Office of Dietary Supplements – Vitamin D. National Institutes of Health. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/. Published February 11, 2018. Accessed May 5, 2017.
  1. Pfotenhauer KM, Shubrook JH. Vitamin D Deficiency, Its Role in Health and Disease, and Current Supplementation Recommendations. The Journal of the American Osteopathic Association. http://jaoa.org/article.aspx?articleid=2625276. Published May 1, 2017. Accessed May 5, 2017.
  2. American Osteopathic Association. Widespread vitamin D deficiency likely due to sunscreen use, increase of chronic diseases, review finds. ScienceDaily. https://www.sciencedaily.com/releases/2017/05/170501102258.htm. Published May 1, 2017. Accessed May 5, 2017.
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