#VITAMIN R REVIEW SKIN#

#VITAMIN R REVIEW SKIN#

As mentioned, most of our vitamin D is produced in the skin through sunlight exposure, whereas only about 20% is derived from foods 17. Instead, vitamin D2 is derived from fungal sources, such as mushrooms and yeast. A secondary way to get vitamin D3 is by eating foods such as fatty fish or egg yolk. In the skin, ultraviolet-B radiation produces vitamin D3 from precursor 7-dehydrocholesterol. In humans, vitamin D is found in two isoforms: vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol) 18. Its increasing prevalence seems to be linked to obesity, lifestyle, and reduced sun exposure 17. When investigated, vitamin D deficiency is frequently diagnosed in women of reproductive age 14-16. Animal and human studies highlighted that vitamin D is also involved in modulation of the reproductive process in both women and men 10,11 due to expression of the vitamin D receptor (VDR) and of 1-alpha-hydroxylase in reproductive tissues such as the ovaries, testes, uterus, placenta, pituitary gland, and in the hypothalamus 11-13. Observational studies clearly demonstrated that low serum levels of vitamin D correlated with several chronic conditions including endocrine diseases 2-5, with cancer development and progression 6,7, and with autoimmune disorders 8,9. However, increasing evidence suggests that there are also several non-skeletal benefits of vitamin D. It is well established that vitamin D maintains calcium homeostasis and promotes bone mineralization 1.

Around of 80-90% of our vitamin D is synthesized in the skin through sunlight exposure the rest derives from food 1. It also plays an important role in the development of insulin resistance. While there are numerous conflicting studies on the relationship of vitamin D levels with AMH levels, PCOS and endometriosis, vitamin D, influencing endometrial thickness, plays a considerable role in intracytoplasmic sperm injection and in in vitro fertilization. This deficiency is correlated with a variety of adverse outcomes in different conditions associated with infertility. Vitamin D deficiency is very common in fertile and infertile women. Although some studies showed no overall correlation between vitamin D and anti-Müllerian hormone (AMH) levels in the infertile population, vitamin D deficiency could be associated with lower ovarian reserve in women aged >40 years. The literature provides scarce data on primary dysmenorrhea and uterine leiomyoma in relation to vitamin D. Contrasting results were found regarding vitamin D levels in IVF and PCOS, as well as on the role of vitamin D in endometriosis. Findings were grouped under the headings: in vitro fertilization, polycystic ovary syndrome (PCOS), endometriosis, primary dysmenorrhea, uterine leiomyoma, ovarian reserve. The final number of papers included in our review was 49. The search was conducted by matching the term “vitamin D” with the following terms: “infertility”, “in vitro fertilization”/“IVF”, “polycystic ovary syndrome”/“PCOS” (and also “insulin-resistance”), “endometriosis”, “primary dysmenorrhea”, “uterine leiomyoma”, “ovarian reserve”. The PubMed database was searched for eligible studies published by May 10th 2020. The authors provide an overview of clinical data on the role of vitamin D in conditions possibly associated with female infertility. Vitamin D, in both women and men, has been shown to be involved in modulation of the reproductive process, due to expression of the vitamin D receptor and of 1-alpha-hydroxylase in reproductive tissues such as the ovaries, testes, uterus, placenta, pituitary gland, and in the hypothalamus.

Vitamin r review