Scientific Opinion on the substantiation of health claims related to vitamin B12 and red blood cell formation (ID 92, 101), cell division (ID 93), energy-yielding metabolism (ID 99, 190) and function of the immune system (ID 107) pursuant to Article 13(1) of Regulation (EC) No 1924/2006
Słowa kluczowe:
Vitamin B12
cell division
energy metabolism
immune system
red blood cells
vitamins
1. Charakterystyka żywności / składnika
The food constituent that is the subject of the health claims is vitamin B12, which is a specific group of cobalt-containing corrinoids with biological activity in humans. Recommended biochemical nomenclature restricts the term vitamin B12 for the particular form of cobalamin known as cyanocobalamin and all cobalamins exhibiting qualitatively the biological activity of cyanocobalamin. Cobalamins do not occur in plants but are synthesised by certain bacteria, fungi and algae, which constitute the ultimate source of all cobalamin found in nature (Green, 2005). Vitamin B12 is a well recognised nutrient and is measurable in foods by established methods.
Vitamin B12 occurs naturally in foods and it is authorised for addition to foods and for use in food supplements (Annex I of the Regulation (EC) No 1925/20064 and Annex I of Directive 2002/46/EC5). This evaluation applies to vitamin B12 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, vitamin B12, which is the subject of the health claims is sufficiently characterised.
2. Znaczenie oświadczenia dla zdrowia człowieka
2.1. Tworzenie erytrocytów (czerwonych krwinek) (ID 92, 101)
The claimed effects are “blood formation” and “blood function”. The Panel assumes that the target population is the general population. The Panel considers that normal red blood cell formation is beneficial to human health.
2.2. Podziały komórek (ID 93)
The claimed effect is “cell division”. The Panel assumes that the target population is the general population. The Panel notes that cell division is a crucial process for tissue growth and development and for tissue maintenance through cell turnover.
The Panel considers that normal cell division is beneficial to human health.
2.3. Metabolizm energetyczny (ID 99, 190)
The claimed effect is “energy metabolism”. The Panel assumes that the target population is the general population. The Panel considers that normal energy-yielding metabolism is beneficial to human health.
2.4. Funkcjonowanie układu odpornościowego (ID 107)
The claimed effect is “the role of vitamins and minerals in immunity“. The Panel assumes that the target population is the general population. The Panel considers that the normal function of the immune system is beneficial to human health.
3. Naukowe uzasadnienia wpływu na zdrowie człowieka -
The two forms of vitamin B12 that function as coenzymes for metabolic reactions are methylcobalamin and deoxyadenosylcobalamin.
3.1. Tworzenie erytrocytów (czerwonych krwinek) (ID 92, 101)
Vitamin B12, in association with folate, is needed for the metabolism of methyl groups involved in the synthesis of nucleotides, so that vitamin B12 deficiency leads to impaired DNA synthesis that results in megaloblastic anaemia. The nuclei of the developing hematopoietic precursor cells in the bone marrow remain immature compared with the cytoplasm, which is maturing normally. The morphological result is a macrocytic red blood cell (high mean cell volume). Many cells die in the bone marrow, possibly by apoptosis (Stabler, 2006). The Panel concludes that a cause and effect relationship has been established between the dietary intake of vitamin B12 and normal red blood cell formation.
3.2. Podziały komórek (ID 93)
Vitamin B12 is required as coenzyme in the form of methylcobalamin for the transmethylation of homocysteine to methionine by 5-methyl-tetrahydrofolate. Methionine is an essential amino acid that is necessary for protein synthesis but is also a crucial methyl donor after activation to S-adenosylmethionine (SAM). SAM is a source of methyl groups for the synthesis of creatine phospholipids and neurotransmitters, and for DNA, RNA, and protein methylation (Green, 2005; Stabler, 2006). The Panel concludes that a cause and effect relationship has been established between the dietary intake of vitamin B12 and normal cell division.
3.3. Metabolizm energetyczny (ID 99, 190)
Vitamin B12 is required as coenzyme in the form of deoxyadenosylcobalamin for the isomerisation of methylmalonyl coenzyme A (CoA) to succinyl-CoA, which is an intermediate in the citric acid cycle (Stabler, 2006).
The Panel concludes that a cause and effect relationship has been established between the dietary intake of vitamin B12 and normal energy-yielding metabolism.
3.4. Funkcjonowanie układu odpornościowego (ID 107)
Vitamin B12 interferes with immune function through its involvement in nucleic acid and protein biosynthesis in concert with vitamin B6 and folate. In human studies with vitamin B12-deficient patients an abnormally high CD4+/CD8+ ratio and suppressed NK cell activity were reported, which could be restored by administration of vitamin B12. Another finding was an impaired antibody response to pneumococcal polysaccharide vaccine, suggesting that the decreased availability of vitamin B12 to rapidly proliferating B lymphocytes may impair clonal expansion and synthesis of specific immunoglobulins (Wintergerst et al., 2007). The Panel concludes that a cause and effect relationship has been established between the dietary intake of vitamin B12 and normal function of the immune system.
4. Uwagi do zaproponowanego brzmienia oświadczenia
4.1. Tworzenie erytrocytów (czerwonych krwinek) (ID 92, 101)
The Panel considers that the following wording reflects the scientific evidence: “vitamin B12 contributes to normal red blood cell formation”.
4.2. Podziały komórek (ID 93)
The Panel considers that the following wording reflects the scientific evidence: “vitamin B12 contributes to normal cell division”.
4.3. Metabolizm energetyczny (ID 99, 190)
The Panel considers that the following wording reflects the scientific evidence: “vitamin B12 contributes to normal energy metabolism”.
4.4. Funkcjonowanie układu odpornościowego (ID 107)
The Panel considers that the following wording reflects the scientific evidence: “vitamin B12 contributes to a normal function of the immune system”.
5. Warunki i możliwe ograniczenia stosowania oświadczenia
The Panel considers that in order to bear the claims a food should be at least a source of vitamin B12 as per Annex to Regulation (EC) No 1924/2006. Such amounts can be easily consumed as part of a balanced diet. The target population is the general population. Tolerable Upper Intake Levels (UL) have not been established for vitamin B12 in children, adolescents and adults.
Wnioski
On the basis of the data presented, the Panel concludes that:
The food constituent, vitamin B12, which is the subject of the health claims is sufficiently characterised.
Red blood cell formation (ID 92, 101)
The claimed effects are “blood formation” and “blood function”. The target population is assumed to be the general population. Normal red blood cell formation is beneficial to human health. A cause and effect relationship has been established between the dietary intake of vitamin B12 and normal red blood cell formation. The following wording reflects the scientific evidence: “vitamin B12 contributes to normal red blood cell formation”.
Cell division (ID 93)
The claimed effect is “cell division”. The target population is assumed to be the general population. Normal cell division is beneficial to human health. A cause and effect relationship has been established between the dietary intake of vitamin B12 and normal cell division. The following wording reflects the scientific evidence: “vitamin B12 contributes to normal cell division”.
Energy-yielding metabolism (ID 99, 190)
The claimed effect is “energy metabolism”. The target population is assumed to be the general population. Normal energy-yielding metabolism is beneficial to human health. A cause and effect relationship has been established between the dietary intake of vitamin B12 and normal energy-yielding metabolism. The following wording reflects the scientific evidence: “vitamin B12 contributes to normal energy metabolism”.
Function of the immune system (ID 107)
The claimed effect is “the role of vitamins and minerals in immunity”. The target population is assumed to be the general population. Normal function of the immune system is beneficial to human health. A cause and effect relationship has been established between the dietary intake of vitamin B12 and normal function of the immune system. The following wording reflects the scientific evidence: “vitamin B12 contributes to a normal function of the immune system”.
Conditions and possible restrictions of use
In order to bear the claim a food should be at least a source of vitamin B12 as per Annex to Regulation (EC) No 1924/2006. Such amounts can be easily consumed as part of a balanced diet. The target population is the general population.