Vitamin D: how importanti is it?
The interest in vitamin D and its functions has increased greatly in recent years; today many evidences justifies the importance of taking the appropriate amounts of this vitamin for bone health, in all stages of life 1:
• during fetal development for the correct growth of the tissues;
• from the early days of the infant’s life to prevent rickets;
• during childhood and adolescence for rapid growth;
• in adulthood to reduce the risk of fractures.
However, vitamin D deficiency is still very common due to nutritional deficiencies or lack of exposure to sunlight 2.
It is important to remember that the concentrations of vitamin D in foods are scarce and achieve significant levels in fatty fish, some fish oils and egg yolk. Also breast milk contains amounts of vitamin D insufficient for the needs of a baby 3.
In addition, vitamin D is produced in the skin and activated by light of the sun, but sun exposure varies according to the seasons, weather conditions, pollution and lifestyle.
New evidence suggests that vitamin D plays a role in the prevention of diseases infettive4, autoimmune diseases (multiple sclerosis) 5, certain cancers (breast, ovarian, colorectal, prostate) 6-8 and diabetes mellitus type 2 and type 1. 9, 10
Currently a lot of sweat are underway to evaluate the therapeutic effects of vitamin D supplementation in various disease states.
References:
1 Giuseppe Di Mauro, Lorenzo Mariniello, Dora Di Mauro. Vitamina D implicazioni sulla salute scheletrica e non scheletrica.
2 Thacher TD, Fischer PR, Strand MA, Pettifor JM. Nutritional rickets around the world: causes and future directions. Ann Trop Paediatr. 2006;26(1):1-16.
3 Andian N, Yordam N, Ozon A. risk factors for vitamin D deficiency in breast-fed newborns and their mothers.
4 Rehman PK. Sub-clinical rickets and recurrent infection. J Trop Pediatr. 1994; 40(1):58.
5 Hayes CE. Vitamin D: a natural inhibitor of multiple sclerosis. Proc Nutr Soc 200;59(4):531-535.
6 Garland FC, Garland CF, Gorham ED, Young JE. Geographic variation in breast cancer mortality in the United states: a hypothesis involving exposure to solar radiation. Prev Med 1990; 19(6):614-622.
7 Holich MF. Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease and osteoporosis. Am J Clin Nutr. 2004;79(3):362-371.
8 Lefkowitz ES, Garland CF. Sunlight, vitamin D and ovarian cancer mortality rates in US woman. Int J Epidemiol. 1994;23(6):1133-1136.
9 Pittas AG, Dawson-Hughes B, Li T et al. Vitamin D and calcium intake in relation to type 2 diabetes in women. Diabetes Care. 2006;29(3):650-656.
10 The Eurodiab Substudy 2 Study Group. Vitamin D supplement in early childhood and risk for type 1 (insulin-dependent) diabetes mellitus. Diabetologia. 1999;42(1):51-5.
