After all, is vitamin D supplementation beneficial?

Vitamin D is a vitamin that has two forms: D3 (Cholecalciferol), synthesized in the skin during sun exposure and present in eggs and fatty fish, and D2 (Ergocalciferol), produced by ultraviolet irradiation of yeast and mushrooms exposed to the sun, this being the form present in supplements and medications. [1]

How do we get vitamin D?

We can obtain vitamin D through our diet, such as by eating oily fish and eggs. However, few foods naturally contain this vitamin. Most vitamin D is produced in the skin through sun exposure. A series of chemical reactions is triggered, involving the liver, skin, and kidneys, leading to the production of 1,25-dihydroxyvitamin D, the biologically active form of vitamin D, also known as calcitriol. [2]

What role does vitamin D play?

Vitamin D not only plays a role in the prevention and treatment of bone diseases, but is also associated with a reduced risk of cancer, cardiovascular, autoimmune, and infectious diseases, as well as various types of mental disorders and overall mortality. [3]

Does vitamin D play a role in preventing fractures?

Yes. A meta-analysis of 12 randomized controlled trials, which included more than 40,000 people over the age of 65, mostly women, looked at whether vitamin D supplementation had any impact on reducing hip fractures. The conclusion was that higher intakes of vitamin D supplements reduced hip fractures by about 20%, while lower intakes failed to offer any benefit in preventing fractures. [4]

What is the maximum safe dose?

The maximum dose of vitamin D, according to the General Directorate of Health (DGS), is 4000 IU per day, that is, the equivalent of more than 200 Izzee meals.

Since Portugal is a sunny country, do the Portuguese get enough vitamin D during their daily lives?

The answer is no. Over the past decade, there has been a huge number of people with suboptimal or deficient vitamin D levels in the general population. [5]

The majority of the Brazilian population has insufficient sun exposure, spending much of the day outdoors. This is compounded by a diet low in vitamin D and calcium, the general population's age, and skin cancer awareness campaigns. It is estimated that more than 40% of the adult Brazilian population is vitamin D deficient, with this figure reaching 75% in various areas of the country during the winter. [6] The main cause of this deficiency is lack of sun exposure, as there is less outdoor activity, and sunscreen reduces ultraviolet radiation by more than 95%, thus reducing vitamin D production by more than 95%. [7]

Izzee is supplemented with vitamin D to ensure a balanced and ideal diet for you, always thinking about today and tomorrow.

References

[1] Keegan RJ, Lu Z, Bogusz JM, Williams JE, Holick MF. Photobiology of vitamin D in mushrooms and its bioavailability in humans. Dermatoendocrinol. 2013 Jan 1;5(1):165-76. doi: 10.4161/derm.23321. PMID: 24494050; PMCID: PMC3897585.

[2] Wacker M, Holick MF. Sunlight and Vitamin D: A global perspective for health. Dermatoendocrinol. 2013 Jan 1;5(1):51-108. doi: 10.4161/derm.24494. PMID: 24494042; PMCID: PMC3897598.

[3] Hossein-nezhad A, Holick MF. Vitamin D for health: a global perspective. Mayo Clin Proc. 2013 Jul;88(7):720-55. doi: 10.1016/j.mayocp.2013.05.011. Epub 2013 June 18th. PMID: 23790560; PMCID: PMC3761874.

[4] Bischoff-Ferrari HA , Willett WC , Wong JB, et al. Prevention of Nonvertebral Fractures With Oral Vitamin D and Dose Dependency : A Meta-analysis of Randomized Controlled Trials . Arch Intern Med 2009;169(6):551–561. doi:10.1001/archinternmed.2008.600

[5] Bjelakovic G, Gluud LL, Nikolova D, Whitfield K, Wetterslev J, Simonetti RG, et al. Vitamin D supplementation for prevention of mortality in adults . Cochrane Database Syst Rev. 2014; 1: CD007470.

[6] Serum levels of 25-hydroxyvitamin D in a healthy population from Northern Portugal, The Journal of Steroid Biochemistry and Molecular Biology, Volume 175, 2018, Pages 97–101, ISSN 0960–0760, https://doi.org/10.1016/j.jsbmb.2016.11.005 .

[7] Felton SJ, Cooke MS, Kift R, et al. Competing beneficial (vitamin D production) and hazardous impact (cutaneous DNA damage) of repeated low-level summer sunlight exposures . Br J Dermatol. 2016;175:1320–8.