Vitamin E and fatty acids in the grey seal (Halichoerus grypus)

Vitamin E levels in serum, liver and blubber (subcutaneous adipose tissue) were determined for 66 male and female grey seals of varying age in the pupping colony on Sable Island in the Northwest Atlantic by high-performance liquid chromatography (HPLC). Fatty acid concentrations were determined for all blubber specimens. Adult males and pups had significantly higher levels of vitamin E and cholesterol in serum than females and juveniles. A close relationship between vitamin E and cholesterol in serum could be observed. Suckling pups had significantly higher levels of vitamin E in liver (191 mg·kg−1) than juveniles and adults (21–41 mg·kg−1). Levels of vitamin E in blubber showed an age-dependent increase, with the highest levels being found in adult males; overall, these levels were much lower than in man. Vitamin E levels in blubber and liver of lactating females were only half that of adult males. This might be due to an intensive transfer of vitamin E from mother to pup during lactation, a process which may also explain the much higher levels of vitamin E in serum and liver of nursing pups. The low levels of vitamin E in blubber of seals might be a result of its high percentage of unsaturated fatty acids (79%). Highest percentage was represented by 18:1, 16:1, 22:6 and 16:0. Pups had lower values of monounsaturated, and a higher percentage of saturated fatty acids compared to mothers.