Fatty acids, C16-18, zinc salts

Specific investigations: other studies

Description of key information

Zinc is an essential element required for the function of a large number of enzymes. It plays a role in DNA and RNA synthesis and many other processes in the body. A zinc deficiency in the diet can lead to notable health effects. Recommended daily zinc levels range from 5 mg/day for infants to 19 mg/day for women during lactation.

Additional information

No data are available on specific toxicity of Fatty acids, C16-18, zinc salts. Data on other zinc compounds have been used, as it is assumed that during exposure or after intake and absorption substance Fatty acids, C16 -18, zinc salts is changed (at least in part) to ionic zinc and that only ionic zinc is determining biological activities. A full read-across of data based on the solubility and a molecular weight correction is considered for Fatty acids, C16-18, zinc salts.

Zinc is essential for growth and development, neurological function, wound healing and immunocompetence. The main clinical manifestations of zinc deficiency are growth retardation, delay in sexual maturation or increased susceptibility to infections.

Important in this context is the maintenance of the physiological zinc homeostasis. Disturbance of this zinc homeostasis through for example excessive zinc exposure have been implicated with neurogenerative diseases like Alzheimer’s or Wilson’s disease undefined or with immunosuppressive effects, but the exact mechanisms have not been elucidated.

There is at this stage no evidence that zinc has any neurotoxicological or immunotoxicological effects under normal zinc exposure conditions and at recommended zinc intake levels. Zinc deficiency, however, adversely affects neurological function and immune competence.

Read-across approach is in accordance to EU RAR Zinc stearate (CAS# 91051-01-3, CAS# 557-05-1) Part II – Human Health. EUR 21168 EN. However, neurotoxicity and immunotoxicity are not specially addressed in the EU RAR. But the EU RAR elaborates on the essential character of the trace element zinc and effects of zinc deficience:

“Zinc is an essential element for humans and animals and it is required for the optimum function of over 200 enzymes. These enzymes include those required for normal acid, protein, and membrane metabolism, as well as cell growth and division. Zinc also plays a role in the regulation of DNA and RNA synthesis (Vallee and Auld, 1990(r); South and Summers, 1990(r); Berg, 1990(r)). Zinc is also a required element for the optimum activity of growth hormone and the normal exocrine and endocrine function of the pancreas (Lee et al., 1990(r)).

A zinc deficiency in the diet has been associated with loss of appetite, decreased sense of smell and taste, impaired immune function, poor wound healing and dermatitis. It can also lead to retarded growth and hypogonadism with impaired reproductive capacity. An increased incidence of congenital malformations in infants has also been associated with a zinc deficiency in the mothers (Cotran et al., 1989(r); Elinder, 1986; Sandstead, 1981(r)).

The symptoms of zinc deficiency in children may be different from that of adults. In chronic zinc deficiency, anorexia, diarrhoea, irritability, and short stature may be predominant in children while in adults taste and smell malfunction, hypogonadism, and poor wound healing may appear as early signs. The main symptoms observed during an experimental zinc deficiency in male volunteers were loss of body weight and testicular hypo-function (Prasad, 1983).

The following daily zinc levels are recommended by NAS/NRC (1989(r)):

Infants (0-1 year) 5 mg/day

Children (1-10 years) 10 mg/day

Males (11-51+ years) 15 mg/day

Females (11-51+ years) 12 mg/day

Pregnant women 15 mg/day

During lactation (first 6 months) 19 mg/day, (next 6 months) 16 mg/day

Other authorities such as the EU (1993) or the Voedingsraad (1992) recommended somewhat lower daily levels of 9-10 mg/day and 7-9 mg/day for males and females, respectively.

Conclusion on biological function and recommended levels

Zinc is an essential element required for the function of a large number of enzymes. It plays a role in DNA and RNA synthesis and many other processes in the body. A zinc deficiency in the diet can lead to notable health effects. Recommended daily zinc levels range from 5 mg/day for infants to 19 mg/day for women during lactation.”