From reducing sports injuries to cardiovascular health, vitamin D is best described as the philharmonic conductor of fat soluble vitamins. The symphony of players for optimum health includes Vitamin D, along with vitamins E, K and A.
Most doctors today recognize the importance of vitamin D, as it has taken center stage in health issues, and will recommend supplementation to replenish our stores. However, depending on where we live and what season it is, many of us lose access to the “sunshine vitamin”, vitamin D. Deficiencies of vitamin D have been linked to heart disease, depression, weight gain, cancer and osteoporosis.
A 2018 study even found inadequate vitamin D levels associated with a higher prevalence of muscle injuries in NFL players. However, like most nutrients in the body, vitamin D does not act alone, but is a member of an entire orchestra of fat-soluble vitamins that work synergistically.
Other prestigious members of the fat-soluble vitamin family include vitamins A, E and K. We might know vitamin A for its essential role in cellular reproduction and differentiation, its importance for good vision and its necessity for the proper development of the embryo and fetus, healthy thyroid function and skin integrity.
A lesser known fact is that vitamin A plays a role in the absorption of vitamin D. Vitamin D may only be able to activate its receptor with the direct cooperation of vitamin A.
According to a study in Molecular Cell Biochemistry, “Vitamin A status modulates the retinoid X receptor,” there exists what is called an “allosteric communication” triggered by the retinoid X receptor ligand with a role in vitamin D signaling. The two vitamins essentially communicate with one another.
In a study, The Role of Fat-Soluble Vitamins in Osteoarthritis Management, we also witness the beautiful dynamic between vitamins D, E and K. Although the precise pathological mechanism behind this chronic degenerative disease is unclear, the nutritional roles of the fat-soluble vitamins are well understood.
“Vitamin D plays an important role in the development and maintenance of the skeleton, as well as bone and cartilage metabolism, and its deficiency is implicated in the pathological process of OA. Vitamin E enhances chondrocyte growth and exhibits an anti-inflammatory activity, as well as plays an important role in the prevention of cartilage degeneration.” ~ Xiao-yan Zheng, MD, 2018
A study in Nutrients touts the collective benefit of the total antioxidant capacity of the combination of vitamins A and E. Vitamins A and E are known to limit free-radical oxidation, which has been associated with preventing or delaying chronic disease, including metabolic syndrome.
Vitamin K, known for its injectable form at birth and its 
necessity for normal blood clotting, also plays a more-than-supportive role with vitamin D in protecting against cardiovascular disease. One study compared taking vitamin K2 with vitamin D and vitamin D alone to test the progression of coronary artery calcification. The data showed a slower progression of calcification with the addition of vitamin K2 than with vitamin D alone. Also, vitamin K is often added to vitamin D supplements to aid in its absorption.
In summary, science notes the talents and potencies of each of the fat-soluble vitamins. Our bodies, however, are miraculous networks of reactions and synergy between nutrients so recognizing the symphony played within the ensemble of fat-soluble vitamins will help keep our bodies healthy, and in harmony.
Sources:
Rebolledo BJ, et al. The Association of Vitamin D Status in Lower Extremity Muscle Strains and Core Muscle Injuries at the National Football League Combine. Arthroscopy. 2018 Apr;34(4):1280-1285. doi: 10.1016/j.arthro.2017.10.005.
Ribot J, Felipe F, Bonet ML, Palou A. Retinoic acid administration and vitamin A status modulate retinoid X receptor alpha and retinoic acid receptor alpha levels in mouse brown adipose tissue. Mol Cell Biochem. 2004 Nov;266(1-2):25-30.
Sánchez-Martínez R, Castillo AI, Steinmeyer A, Aranda A. The retinoid X receptor ligand restores defective signaling by the vitamin D receptor. EMBO Rep. 2006 Oct;7(10):1030-4.
Zheng XY, Liang J, Li YS, Tu M. Role of Fat-Soluble Vitamins in Osteoarthritis Management. J Clin Rheumatol. 2018 Apr;24(3):132-137. doi:10.1097/RHU.0000000000000587.
Kim S, Song Y, Lee JE, Jun S, Shin S, Wie GA, Cho YH, Joung H. Total Antioxidant Capacity from Dietary Supplement Decreases the Likelihood of Having Metabolic Syndrome in Korean Adults. Nutrients. 2017 Sep 22;9(10). pii: E1055. doi: 10.3390/nu9101055.
Ilona Kurnatowska et al. Epidemiology – cardiovascular outcomes, Nephrology Dialysis Transplantation, Volume 28, Issue suppl_1, May 2013, Pages i352–i357, https://doi.org/10.1093/ndt/gft130
