Introduction to Human Nutrition

126 Introduction to Human Nutrition useful to compare an individual’s energy intake with some measure or calculation of their ex ...

Dietary Reference Standards 127 and has responded by providing foods to address particular perceived needs, and more informative ...

128 Introduction to Human Nutrition The lowest defi ned intake level [lowest threshold intake (LTI), lower reference nutrient in ...

Dietary Reference Standards 129 of defi ciency, and then adding back the nutrient until the symptoms are cured or prevented. Dif ...

130 Introduction to Human Nutrition necessarily take account of physiological adaptations (e.g., increased effi ciency of absorp ...

Dietary Reference Standards 131 animals can be used in experiments that would not be possible in humans, such as lifelong modifi ...

8 The Vitamins David A Bender Key messages The vitamins are a chemically disparate group of compounds with a variety of functio ...

The Vitamins 133 known as vitamin B 2. Biotin is still sometimes called vitamin H. Vitamin K was discovered by Henrik Dam, in De ...

134 Introduction to Human Nutrition a role in vision, as the prosthetic group of the light- sensitive proteins in the retina, an ...

The Vitamins 135 vegetables, as well as in liver, margarine, and milk and milk products. In addition to their role as precursors ...

136 Introduction to Human Nutrition Only a proportion of carotene undergoes oxidation in the intestinal mucosa, and a signifi ca ...

The Vitamins 137 10 ′- and 12′-apo-carotenals, which are oxidized to yield retinoic acid, but are not precursors of retinol or r ...

138 Introduction to Human Nutrition CH 2 OH CH 3 H 3 C CH 3 CH^3 CH^3 all-trans-Retinol CH 3 H 3 C CH 3 CH^3 H 3 C 11-cis-Retino ...

The Vitamins 139 different tissues, and at different stages in develop- ment, and retinoic acid is essential for the normal resp ...

140 Introduction to Human Nutrition This is an invasive procedure that cannot be consid- ered for routine investigations and pop ...

The Vitamins 141 extrapolation, it has been assumed that retinol is also teratogenic, although there is little evidence. In case ...

142 Introduction to Human Nutrition HO7-Dehydrocholesterol OH CH 3 CH 2 HO H C 3 OH Previtamin D Tachysterol Vitamin D calciol ( ...

The Vitamins 143 that accumulates in the skin but not other tissues) undergoes a non-enzymic reaction on exposure to UV light, y ...

144 Introduction to Human Nutrition ● Calcitriol acts to reduce its own synthesis and increase formation of 24-hydroxycalcidiol, ...

The Vitamins 145 Osteomalacia also occurs in the older people. Here again the problem may be inadequate exposure to sunlight, bu ...