Background: There is increasing evidence that postprandial triacylglycerol-rich lipoproteins may be related to atherogenic risk. Objective: The objective was to investigate the effect of individual fatty acid intakes on postprandial plasma lipoprotein triacylglycerol and cholesterol concentrations, plasma fatty acids, and preheparin lipoprotein lipase and cholesterol ester transfer protein (CETP) activities. Design: Six test fats high (≈43% by wt) in stearic acid, palmitic acid, palmitic + myristic acid, oleic acid, elaidic acid (trans 18:1), and linoleic acid were produced by interesterification. After having fasted for 12 h, 16 healthy young men were served the individual test fats incorporated into meals (1 g fat/kg body wt) in random order on different days separated by washout periods. Blood samples were drawn before and 2, 4, 6, and 8 h after the meals. Results: Different responses to the test-fat meals were observed for plasma lipoprotein triacylglycerol and cholesterol concentrations, plasma fatty acid concentrations, and lipoprotein lipase and CETP activities (diet × time interaction: 0.001 < P < 0.05). Intake of the long-chain saturated fatty acids stearic and palmitic acids resulted in a relatively lower lipemic response than did intake of the unsaturated fatty acids, probably because the saturated fatty acids were absorbed less and at a lower rate; therefore, the lipemic response took longer to return to postabsorptive values. Conclusions: Fatty acid chain length and degree of saturation appear to affect the extent and duration of lipemia and affect hepatic output indirectly. These effects may not be mediated via effects on lipoprotein lipase and CETP activities.

In food databases, the specific contents of vitamin D₃ and 25-hydroxyvitamin D₃ in food have been implemented in the last 10 years. No consensus has yet been established on the relative activity between the components. Therefore, the objective of the present study was to assess the relative activity of 25-hydroxyvitamin D₃ compared to vitamin D₃. The design was a parallel study in pigs (n 24), which from an age of 12 weeks until slaughter 11 weeks later were fed approximately 55 μg vitamin D/d, as vitamin D₃, in a mixture of vitamin D₃ and 25-hydroxyvitamin D₃, or 25-hydroxyvitamin D₃. The end-points measured were plasma 25-hydroxyvitamin D₃, and in the liver and loin the content of vitamin D₃ and 25-hydroxyvitamin D₃. Vitamin D₃ and 25-hydroxyvitamin D₃ in the feed did not affect 25-hydroxyvitamin D₃ in the plasma, liver or loin differently, while a significant effect was shown on vitamin D₃ in the liver and loin (P < 0·001). 25-Hydroxyvitamin D₃ in the plasma, liver and loin significantly correlates with the sum of vitamin D₃ and 25-hydroxyvitamin D₃ in the feed (P < 0·05). Therefore, 25-hydroxyvitamin D₃ should be regarded as having the same activity as vitamin D₃ in food databases. Sole use of 25-hydroxyvitamin D₃ as a vitamin D source in pig feed will produce liver and meat with a negligible content of vitamin D₃, while an increased content of vitamin D₃ in the feed will produce liver and meat with increased content of both vitamin D₃ and 25-hydroxyvitamin D₃.