Vitamin D and Your Health
Despite living in the sunshine state of California, it is still common to hear that your Vitamin D level is low and supplementation needs to be started.
Why is your Vitamin D level low?
In part, our sedentary and indoors lifestyles are to blame for epidemic low levels along with the fact that food sources of Vitamin D are limited and provide little daily value of this vitamin. Additionally, with the growing obesity epidemic, as fat mass increases, more Vitamin D is draw up into fat (adipose) cells. Therefore, as weight, related to fat increase, goes up, levels of Vitamin D go down as more of this fat-soluble vitamin becomes stored into fat cells.
What happens when your Vitamin D level is low?
Current Recommended Daily Allowance (RDA) of Vitamin D stands at 600 IU (15 micrograms) for adults between the ages of 18 to 50. While Vitamin D aids in a variety of body functions, the most well-known is helping in calcium absorption and good bone health. Studies have also shown that greater Vitamin D supplementation results in greater calcium absorption when calcium intake recommendations are met (Shapses et al., 2013). In addition to bone health, Vitamin D also plays a role in supporting immune function, reducing risk of cardiovascular disease and risk of Type 2 Diabetes (Lim et al., 2013; Shapses et al., 2013). While one often thinks of increased BMI (overweight and obese body weight) in relation to risk of Diabetes, studies have also shown that low Vitamin D levels are also associated with increased risk of diabetes irrelevant of weight (Lim et al., 2013). Additionally, low Vitamin D levels have shown increased incidents of coronary artery stenosis (hardening of the arteries) in elderly populations, as well as some cancers, hypertension (high blood pressure) and cardiovascular disease (Lim et al., 2013). Lastly, low Vitamin D levels in pregnant women is also associated with greater risks of bone loss, low fetus bone mineral content, low birth weight, autoimmune disease, cancers, occurrence of cesarean delivery, preeclampsia, preterm labor, bacterial vaginosis (Taheri et al., 2014).
So, what can you do if you are low on Vitamin D?
Nowadays, it is easy to supplement with a Vitamin D pill to improve your levels. Since Vitamin D is a fat-soluble vitamin it can take a while to build up levels and studies have shown that supplementing with 2,000-2,5000 IU of vitamin D for a period of 2-3 months can lead to improved Vitamin D status (Dasarathy et al., 2017; Shapses et al., 2013; Taheri et al., 2014). Additionally, about 15 minutes of sun exposure without any sunblock can allow your skin to produce the needed vitamin internally. This does have its limitations, as those with darker skin tones and older persons cannot produce as much Vitamin D as light or fair skinned persons. While getting your daily does of sunshine has other benefits as well, some may still need to consider adding supplementation of Vitamin D to improve currently low levels.
Dasarathy, J.; Varghese, R.; Feldman, A.; Khiyami, A.; McCullough, A.; Dasarathy, S. (Aug 2017). Patients with Nonalcoholic Fatty Liver Disease Have a Low Response Rate to Vitamin D Supplementation. The Journal of Nutrition, 147 (10), pp. 1938-1946.
Lim, S.; Kim, M. J.; Lim, S.; Choi, S. H.; Shin, C. S.; Park, K.; Jang, H.; Billings, L.; Meigs, J. (March 2013). Association of Vitamin D Deficiency with Incidence of Type 2 Diabetes in High-Risk Asian Subjects. The American Journal of Clinical Nutrition, 97 (3), pp. 524-530.
Shapses, S.; Sukumar, D.; Schneider, S.; Schlussel, Y.; Sherrell, R.; Field, M. P.; Ambia-Sobhan, H. (March 2013). Vitamin D Supplementation and Calcium Absorption During Caloric Restriction: A Randomized Double-blind Trial. The American Journal of Clinical Nutrition, 97 (3), pp. 637-645. https://doi.org/10.3945/ajcn.112.044909.
Taheri, M.; Baheiraei, A.; Rahimi Foroushani, A.; Modarres, M. (Jan 2014). Resolving Vitamin D Deficiency in the Preconception Period among High-Risk Reproductive Women: A Randomized Controlled Trial. Iran Red Crescent Medical Journal, 16 (1). DOI: 10.5812/ircmj.11175.