Vitamin D is often called the sunshine vitamin because it can be obtained from the sun and can physiologically “brighten” your day by affecting mood and neurological function. Research indicates that vitamin D may benefit many health conditions such as cancer, osteoporosis, and depression. Despite this, it is estimated that over 1 billion people have a vitamin D deficiency or insufficiency.
Vitamin D is an essential vitamin required for healthy musculoskeletal and neurological functioning in the human body. It may be obtained either from dietary sources or produced by the skin upon UVB sun exposure. Very few foods contain vitamin D; the highest sources may be found in oily fish such as salmon, mackerel, herring, and fortified foods. Fortified foods however are often inadequate to supplement the body’s daily requirements. Sun exposure accounts for more than 90% of the vitamin D requirement for most individuals, but little exposure to sunshine (being bound indoors) and never exposing the skin to direct sunlight without sun protection (due to fear of skin cancer) has led to increased risk of vitamin D deficiency. Other factors that affect sun exposure/exposure to UVB radiation include latitude, season and time of day. Cities at latitudes greater than 34 degrees N, and with increased cloud cover will have lower sun exposure (Vancouver is 49 degrees N and receives more than its fair share of cloudy days!).
Vitamin D deficiency can contribute to bone disorders such as osteopenia, osteoporosis, and fractures in adults, as well as an increased risk of common cancers, autoimmune diseases, infectious diseases, and mental disorders such as depression and seasonal affective disorder (which is highly prevalent in B.C.). Although it is important to protect the skin from excessive sun exposure to reduce the risk of skin cancer, moderate amounts of unprotected sun exposure are healthy and may be necessary to maintain healthy vitamin D levels. For more information on safely maintaining your vitamin D levels, ask your naturopathic doctor for tips on healthy sun exposure and/or supplementing vitamin D.
Note: Sunscreen with a sun protection factor of 15 absorbs 99% of incident UVB radiation and will, therefore, reduce vitamin D synthesis in the skin by 99%!
Check out the Environmental Working Group’s list of sunscreen ingredients to avoid: https://www.ewg.org/sunscreen
Holick, M.F., Chen, T.C. (2008) Vitamin D deficiency: a worldwide problem with health consequences. American Journal of Clinical Nutrition 87: 1080S – 6S.
Penckofer, S., Kouba, J., Bryn, M., Estwing Ferrans, C. (2010) Vitamin D and Depression: Where is all the Sunshine? Issues in Mental Health Nursing 31(6) 385 – 393