Vitamin D is a fat-soluble, steroid-like vitamin that we naturally synthesize in the body when our skin is in contact with UVB rays. Through a series of biochemical reactions, vitamin D turns into its active form, ready to support calcium balance, bone health, cardiovascular function, brain development and healthy immune function, to name a few.
A lack of vitamin D has been linked to a number of various health conditions, including the more obvious conditions of rickets in children and osteomalacia in adults, both conditions characterized by soft, brittle bones. Recent research has also discovered links between other conditions such as cancer, asthma, depression, seasonal affective disorder (SAD), autoimmune disease and Alzheimer’s disease. The take home is that vitamin D is incredibly important in the body and many different organs and systems depend on sufficient levels.
So how do you know if you’re deficient in vitamin D or not?
A simple way is to get your vitamin D levels tested. As we move into the fall and winter seasons, we are less likely to be getting UVB exposure from the sun. Testing levels and supplementing accordingly can go a long way to help prevent significant vitamin D depletions that can happen in the winter months and is particularly helpful for those who have a tendency to suffer from seasonal affective disorder, a mood disorder which leads to depressive symptoms moreso in the wintertime.
Vitamin D can be tested either by a blood draw or a simple finger prick test. While the reference range for appropriate vitamin D levels is quite vast, it is recommended to make sure your level is higher than 75 nmol/L (Vieth 2011). But beware: more vitamin D is not necessarily a good thing. Because vitamin D is a fat-soluble compound, it can build up in fatty tissue over time and potentially lead to toxicity. Supplementing accordingly based on your current lab values and retesting every 4-6 months is recommended to avoid overdosing. A qualified health care practitioner with an awareness of how to appropriately supplement with vitamin D is a good place to start to make sure that your levels are adequate and that you are supplementing appropriately if needed.
Vieth, R. (2011 Aug). Why the minimum desirable serum 25-hydroxyvitamin D level should be 75 nmol/L (30ng/ml). Best Pract Res Clin Endocrinol Metab. 25(4):681-91. Doi: 10.1016/j.beem.2011/06/009.
Vitamin D Council (n.d.). Information on the Latest Vitamin D News and Research. Retrieved from: www.vitamindcouncil.org