Winter 2021 Newsletter
By Dr. Audrey Folsom, DHSc, MSHS, MT(ASCP), Assistant Professor of Clinical Lab Sciences, and Mr. Eric West, MBA, DTR, Assistant Professor of Dietetics
Arkansas State University
Vitamin D deficiency and insufficiency affects individuals across all ethnicities and age groups, but older adults are especially vulnerable. Vitamin D deficiency is a widespread problem, which is attributed to many different factors, including lifestyle and environmental factors.
Vitamin D is an essential component for bone health, helping stave off the development of osteomalacia (bone softening), aiding in preventing muscle weakness, and minimizing bone fractures due to falls. The absorption of vitamin D through UVB-irradiation from sun exposure becomes less efficient in older adults, therefore vitamin D deficiency has become more prevalent in this population (Boucher, 2012). Other factors such as reduced appetite, taking multiple medications, and being under stress add to the prevalence of this deficiency. (Boucher, 2012; Kweder & Eidi, 2018)
Aside from the well-known association between vitamin D and bone health, there have been studies that indicate a correlation between low levels of the vitamin and an increased risk of developing oral, gastrointestinal, urinary, and even respiratory infections (Kweder & Eidi, 2018). Vitamin D has several critical roles in immunity and a deficiency can lead to a dysfunctional immune system. Additionally, if the deficiency is sustained, it can lead to the development of autoimmune conditions or cancers (AACC, 2020). Moreover, research indicates an association between low levels of vitamin D and diseases associated with aging such as cognitive decline, depression, osteoporosis, cardiovascular disease, hypertension, type 2 diabetes, and cancer (Meehan & Penckofer, 2014). With the high prevalence of vitamin D deficiency and its underestimation from many physicians, vitamin D deficiency has become a worldwide health issue (Kweder & Eidi, 2018).
A lack of vitamin D production by the skin during the winter months has been linked to Seasonal Affective Disorder (SAD), also known as the “winter blues”. Depression is linked to lower blood levels of vitamin D (Anglin, Samaan, Walter, & McDonlad, 2018). Normally, the body can manufacture enough vitamin D during the spring, summer and fall months to last through the winter. The body can store vitamin D in the liver and in fat cells (Harvard Health Publishing, 2007), and then use it to get through a winter season. However, because we now have desk jobs or work inside, and use sunscreen when we are outside during the summer, our body struggles to make and store enough to last through the winter months.
While the deficiency is commonly seen in the older adult, there are other contributing risk factors. They include dark skin pigmentation, impaired or poor skin integrity, reduced time spent outdoors and reduced exposure to sunlight, having a body mass index (BMI) greater than 30, and impaired renal function. It is also noted that females are at higher risk than males for vitamin D deficiency (Meehan & Penckofer, 2014). This higher risk comes from differences in body composition. Females (and overweight people) naturally have a higher body fat percentage than males. Vitamin D is a fat-soluble vitamin that gets trapped in fat cells, where it can no longer be used by the body (Donnelly Michos, n.d.). Therefore, a higher body fat percentage leads to lower vitamin D levels.
The best way to know if a vitamin D deficiency is present is to get tested. A primary care provider can order a 25-hydroxyvitamin D, the most abundant and common form of vitamin D found in the blood. This blood test requires no specific preparation and can be done during a regular check up. Once the results come back, the reference ranges for normal levels are indicated on the report, but it is worth noting that the Endocrine Society defines vitamin D deficiency as a 25-hydroxyvitamin D blood level below 20 ng/mL (50 nmol/liter) and vitamin D insufficiency as a level between 21–29 ng/mL (52.5–72.5 nmol/liter) (AACC, 2020).
If the test levels come back below the normal reference range, it is possible that this is due to a lack of sun exposure or a lack of absorption from the intestines, which is common with many bowel disorders such as irritable bowel syndrome, Crohn’s disease, etc. (AACC, 2020) A primary care provider can make a recommendation for supplementing with vitamin D3, which can be easily purchased at most pharmacies and grocery stores. Blood levels can be checked again after several months of supplementation to see if the dosage is adequate, excessive, or inadequate. It is important to get tested before supplementation is started, as high levels of vitamin D in the blood can lead to an accumulation of calcium in the kidneys and blood vessels, which could cause damage (AACC, 2020).
Foods rich in vitamin D include egg yolks and oily fishes, but the amount required to get enough vitamin D is more than the average person would eat. There are fortified foods such as milk and cereals, but even those do not provide enough. The two remaining solutions are to get more sunshine or to supplement. Getting more sunshine can be tricky for those who live in the northern states due to the low angle of the sun’s rays during the winter months, which decreases UVB absorption by the skin. This doesn’t even factor the increased amount of time we spend indoors due to the winter weather. Therefore, most primary care providers will recommend a supplement to get blood levels up. (Harvard Health Publishing, 2007)
In conclusion, vitamin D is a crucial component of a healthy life, especially in older adults. Adequate levels can help keep the diseases of aging at bay. Vitamin D deficiency can be attributed to our modern lifestyle, which keeps us indoors year-round, as well as other risk factors such as being female, having a darker skin pigmentation, and being overweight. Testing is the only way to know if a deficiency is present, and supplementing with vitamin D should be undertaken under the direction of a primary care provider.
AACC. (2020, December 4). Vitamin D Tests. Retrieved from Lab Tests Online: https://labtestsonline.org/tests/vitamin-d-tests
Anglin, R., Samaan, Z., Walter, S., & McDonlad, S. (2018, January 2). Vitamin D Deficiency and Depression in Adults: Systematic Review and Meta-Analysis. Retrieved from Cambridge University Press: https://www.cambridge.org/core/journals/the-british-journal-of-psychiatry/article/vitamin-d-deficiency-and-depression-in-adults-systematic-review-and-metaanalysis/F4E7DFBE5A7B99C9E6430AF472286860
Boucher, B. J. (2012). The Problems of Vitamin D Insufficiency in Older People. Aging and Disease, 313–329. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3501367/
Donnelly Michos, E. (n.d.). How Does Vitamin D Affect Women’s Health? Retrieved January 7, 2020, from Johns Hopkins Medicine: https://www.hopkinsmedicine.org/health/wellness-and-prevention/how-does-vitamin-d-affect-womens-health
Harvard Health Publishing. (2007, February). Vitamin D and Your Health: Breaking Old Rules, Raising New Hopes. Retrieved from Harvard Health Publishing : https://www.health.harvard.edu/staying-healthy/vitamin-d-and-your-health-breaking-old-rules-raising-new-hopes
Kweder, H., & Eidi, H. (2018). Vitamin D Deficiency in Elderly: Risk Factors and Drugs Impact on Vitamin D Status. Avicenna Journal of Medicine, 139–146. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6178567/
Meehan, M., & Penckofer, S. (2014). The Role of Vitamin D in the Aging Adult. Journal of Aging and Gerontology, 60–71. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4399494/