Regulation of Bile Acid Synthesis by Fat-soluble Vitamins A and D

Regulation of Bile Acid Synthesis by Fat-soluble Vitamins A and D*

Bile acids are required for proper absorption of dietary lipids, including fat-soluble vitamins. Here, we show that the dietary vitamins A and D inhibit bile acid synthesis by repressing hepatic expression of the rate-limiting enzyme CYP7A1. Receptors for vitamin A and D induced expression of Fgf15, an intestine-derived hormone that acts on liver to inhibit Cyp7a1. These effects were mediated t...

Hypertension and the Fat-Soluble Vitamins A, D and E

Hypertension affects populations globally and is thus a public health and socio-economic problem. Macronutrient and micronutrient deficiencies are common in the general population, and may be even more prevalent in hypertensive patients. This study aimed to determine a possible association between hypertension and intake of fat-soluble vitamins A, D and E. Participants were from the cross-secti...

Fat-soluble vitamins.

Regulation of bile acid synthesis.

Bile acids are important physiological agents required for disposal of cholesterol and absorption of vitamins and fats. Bile acids are synthesized from cholesterol in the liver. Enterohepatic circulation of bile acids is very efficient and plays an important physiological role in lipid absorption and secretion, and regulation of bile acid biosynthesis and cholesterol homeostasis. Conversion of ...

Absorption of fat-soluble vitamins and sterols

The molecular structure of the four fat-soluble vitamins and of cholesterol, the major intestinal sterol in man, are shown in Figure 1. In spite of the obvious dissimilarities that exist between these compounds they possess one common feature, namely, they are all nonpolar lipids with extremely low solubilities in aqueous media. Because of this, it is convenient to consider them together when e...