ID 361 -
Cynk
PL: Cynk
EN: Zink
Pdf: zinc
Oświadczenie (4)
- Cynk pomaga w utrzymaniu prawidłowego widzienia
- Cynk przyczynia się do prawidłowego metabolizmu witaminy A
Oświadczenie (2)
- udział w metabolizmie witaminy i procesu widzenia
1. Charakterystyka żywności / składnika
The food constituent that is the subject of the claims is zinc, which is a well recognized nutrient and is measurable in foods by established methods. Zinc occurs naturally in foods and is authorised for addition to foods (Annex I of the Regulation (EC) No 1925/20064 and Annex I of Directive 2002/46/EC5). This evaluation applies to zinc naturally present in foods and those forms authorised for addition to foods (Annex II of the Regulation (EC) No 1925/2006 and Annex II of Directive 2002/46/EC).
The Panel considers that the food constituent, zinc, which is the subject of the health claims, is sufficiently characterised.
2.15. Metabolizm witaminy A (ID 361)
The claimed effect is “involvement in vitamin A metabolism and process of vision”. The Panel assumes that the target population is the general population.
The Panel considers that normal metabolism of vitamin A is beneficial to human health.
2.16. Utrzymanie prawidłowego wzroku (ID 361)
The claimed effect is “involvement in vitamin A metabolism and process of vision”. The Panel assumes that the target population is the general population.
The Panel considers that maintenance of normal vision is beneficial to human health.
3. Naukowe uzasadnienia wpływu na zdrowie człowieka -
Zinc is present in all tissues. It has essential structural, regulatory or catalytic roles in many enzymes. It maintains the configuration of a number of non-enzymatic proteins such as pre-secretory granules of insulin, some mammalian gene transcription proteins and thymulin. It facilitates hormone and receptor binding at membrane and nuclear levels, and it may maintain integrity of biomembranes. Consequently zinc participates in gene expression and in the mechanisms and control of major metabolic pathways involving proteins, carbohydrates, nucleic acids and lipids (SCF, 1993; DoH, 1991). Human zinc deficiency symptoms include retarded growth, depressed immune function, skin lesions, skeletal abnormalities, impaired reproductive ability and behavioural abnormalities such as changes in mood, loss of affect and emotional lability, anorexia, dysfunction of smell and taste, irritability and depression (SCF, 2003; EVM, 2002, Cousins, 2006).
3.14. Metabolizm witaminy A (ID 361)
Zinc participates in the absorption, mobilization, transport and metabolism of micronutrients, including vitamin A, through its involvement in protein synthesis and cellular enzyme functions (IoM, 2001). In humans, cross-sectional studies and supplementation trials have failed to establish a consistent relationship between zinc and vitamin A status. However, a positive association may exist in malnourished populations in which deficiencies of both micronutrient often coexists (IoM, 2001; Christian and West, 1998). Because zinc is required for the synthesis of retinol binding protein (RBP), zinc deficiency influences the mobilization of vitamin A from the liver and its transport into the circulation (IoM, 2001).
The Panel concludes that a cause and effect relationship has been established between the dietary intake of zinc and normal metabolism of vitamin A. However, the evidence provided does not establish that inadequate intake of zinc leading to impaired vitamin A metabolism occurs in the general EU population.
3.15. Utrzymanie prawidłowego wzroku (ID 361)
Zinc regulates the metabolic conversion of retinol to retinaldeyde (retinal) through the zinc-dependent enzyme retinol dehydrogenase. The conversion of retinol to retinal is a critical step in the visual cycle in the retina of the eye (Christian and West, 1998; Grahan, 2001). In retina and retinal pigment epithelium, there is evidence that zinc can modify photoreceptor plasma membranes, regulate the light-rhodopsin reaction, modulate synaptic transmission and serve as an antioxidant (Grahan et al., 2001; Ugarte and Osborne, 2001). A significant reduction in the synthesis of rhodopsin was reported in zinc deficient rats, which was postulated to be owing to impaired protein (opsin and alcohol dehydrogenase) synthesis (IoM, 2001). Zinc deficiency in humans has been shown to result in poor dark-adaptation, which improved after the provision of a therapeutic dose of 220 mg/day of zinc (Morrison, 1978).
The Panel concludes that a cause and effect relationship has been established between the dietary intake of zinc and maintenance of normal vision. However, the evidence provided does not establish that intake of zinc inadequate for the maintenance of normal vision occurs in the general EU population.
4.9. Metabolizm witaminy A (ID 361)
The Panel considers that the following wording reflects the scientific evidence: “Zinc contributes to normal metabolism of vitamin A”.
4.10. Utrzymanie prawidłowego wzroku (ID 361)
The Panel considers that the following wording reflects the scientific evidence: “Zinc contributes to maintenance of normal vision”.
5. Warunki i możliwe ograniczenia stosowania oświadczenia
The Panel considers that in order to bear the claim a food should be at least a source of zinc as per Annex to Regulation (EC) No 1924/2006. The target population is the general population. Such amounts can be easily consumed as part of a balanced diet. Tolerable Upper Intake Levels (UL) have been established for zinc as 25 mg/day in adults and to pregnant and lactating woman. For children and adolescents UL was established as 7 mg/day for 1-3 years, 10 mg/day for 4-6 years, 13 mg/day for 7-10 years, 18 mg/day for 11-14 years and 22 mg/day for 15-17 years (SCF 2003).
Warunki i możliwe ograniczenia stosowania oświadczenia
Minimum 15% RDA per daily dosage as per 90/496/EC
Agency guidance for supplements is that products containing >25 mg of zinc should carry the label advisory statement "'Long term intake [of this amount of zinc]* may lead to anaemia."