These are the main conclusions in a scientific opinion from The Norwegian Scientific Committee for Food Safety (VKM), conducted at the request of the Norwegian Food Safety Authority (Mattilsynet).

Based on the premises described in the scientific opinion, previous international and national risk assessments, and published literature, the other conclusions drawn by VKM are:

- The critical adverse health effect of excess intake of vitamin A is teratogenicity. This effect is the basis for the tolerable upper intake level (UL) of 3000 µg RE/day.

- The most important source of vitamin A in the Norwegian population is diet, followed by food supplements and then cosmetics.

- Topical application of cosmetic products, as estimated in the standard scenarios (0.05% in body lotions and 0.3% in face and hand cream), increases the total exposure to vitamin A (retinol and retinyl esters) in all age groups.

The estimated contribution of retinol and retinyl esters from cosmetics is most prominent for 13-year-old adolescents (23% of UL) and adults (29% of UL).

- In the worst case scenarios based on the assumed increased concentrations in cosmetics (0.3% in body lotions and 1% in face and hand cream), the contribution from cosmetics would further increase the total exposure to vitamin A (retinol and retinyl esters).

The estimated contribution of retinol and retinyl esters from cosmetics would reach 42-58% of the ULs for children, 98% of the UL for 13-year-old adolescents and exceed the UL for adults (115%).

- The contribution from cosmetics is of special concern for women of fertile age, and a total exposure above the UL before and during pregnancy will increase the risk of birth defects.

- For persons who are at higher risk for reduced bone mineral density, osteoporosis and fractures, especially post-menopausal women, a lower guidance level (GL) than the UL has been set, i.e. 1500 µg RE/day. About 10% of adult women in Norway exceed this GL by intake of vitamin A from food and food supplements alone.

The additional contribution from cosmetics increases this proportion to approximately 75%. An increased exposure due to higher concentrations of vitamin A (retinol and retinyl esters) in cosmetic products would further augment the proportion of women at risk of osteoporosis.

- Impaired skin may result in increased absorption of cosmetic products. This can occur in persons with diagnosed atopic dermatitis, in persons with dry skin, and in small children with irritated skin in the nappy area.

- VKM has found no information indicating that long-term use of topical retinoids may induce other local effects in the skin than irritation and erythema. A NTP study indicates that retinol and retinyl palmitate may be photocarcinogenic in mice. However, these data do not provide sufficient information for a risk assessment of this effect of retinol and retinyl esters in cosmetics.