Vitamin D is sometimes referred to as “the sunshine vitamin” because our bodies synthesize vitamin D when our skin is exposed to ultraviolet rays from the sun. It is also categorized as a fat-soluble vitamin because it is found in a few fatty foods, including fish liver oil, beef liver, and egg yolks. More accurately, however, vitamin D should be categorized as a hormone. Vitamin D has activity in most cells of the human body. It increases our ability to absorb calcium, assists in fighting infections, and even improves mood.[i] Vitamin D is also one of the most effective natural treatments for insomnia and can help people fall asleep if taken at night. Deficiency of vitamin D is linked to osteoporosis, multiple sclerosis, chronic fatigue syndrome, depression, type 2 diabetes, heart disease, and at least 16 forms of cancer.[ii]

Everybody absorbs vitamin D from foods and synthesizes it from the sun at different rates. One person might take 4000 IU of vitamin D every day yet have a lower blood level than a person who takes none. Because of this, the best way to determine vitamin D status is with a simple blood test. The Endocrine Society recommended in 2011 a target level of vitamin D in the blood of greater than 30 ng/mL, but other studies suggest that optimal levels should be higher than that. In patients with inflammatory bowel disease, for example, those with blood levels of vitamin D greater than 50 ng/mL consistently had the highest health-related quality of life.[iii] Achieving these levels often requires taking supplemental vitamin D at relatively high doses.

Vitamin D Supplement Pills spilling out of bottle Vitamin D is best absorbed when it is delivered in a fatty acid base. We recommend vitamin D products that are delivered in a base of non-GMO extra virgin olive oil. These products are absorbed almost 3 times better than typical vitamin D supplements. I had a patient with migraine headaches who improved 70% with our protocols, and we were trying to figure out why she wasn’t even better. When we discovered that her vitamin D was in a base of corn oil, we switched her to a more pure source of vitamin D and her improvement jumped to near 100%. A higher quality vitamin made all the difference.

At the Care Group, we routinely monitor our patients’ vitamin D levels. Ask us to check your levels


[i] Shaffer JA, Edmondson D, Wasson LT, et al. Vitamin D supplementation for depressive symptoms: a systematic review and meta-analysis of randomized controlled trials. Psychosom Med. 2014;76(3):190-196.

[ii] Wranicz J, Szostak-Węgierek D. Health outcomes of vitamin D. Part II. Role in prevention of diseases. Rocz Panstw Zakl Hig. 2014;65(4):273-279.

[iii] Hlavaty T, Krajcovicova A, Koller T, et al. Higher vitamin D serum concentration increases health related quality of life in patients with inflammatory bowel diseases. World J Gastroenterol. 2014;20(42):15787-15796.

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About The Care Group: We promote optimal wellness by providing an individualized, functional medicine approach to address root causes rather than simply treating symptoms. We help patients with a wide range of issues including autoimmune/ inflammatory disease, digestive disorders, hormone imbalances, and mood disorders. To learn more about our practice, click here.

About the Author: Dr. Gerard Guillory, MD is Board Certified in Internal Medicine and has published two books on Irritable Bowel Syndrome (IBS). In 1985, he opened The Care Group, PC. Today, his clinic is a Primary Care facility that is a hybrid of functional and traditional medicine treating patients with digestive disorders, autoimmune disease, and other conditions. You can learn more about Dr. Guillory here.