CHAPTER 8 CONCEPTS
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Thiamin, riboﬂavin, niacin, biotin, and pantothenic acid are B vitamins needed to produce ATP from carbohydrate, fat, and protein. Vitamin B6 is important for amino acid metabolism as well as energy production. Folate is a coenzyme that is needed for cell division. Vitamin B12, only found in animal foods, is needed for nerve function and to activate folate. Vitamin C is needed to form connective tissue and acts as a watersoluble antioxidant. Vitamin A is essential for vision, and it regulates cell differentiation and growth. Vitamin D is necessary for bone health. Vitamin E is a fat-soluble antioxidant. Vitamin K is essential for blood clotting.
u s t A Ta s t e J
Do vitamins give you extra energy? Should everyone take folate supplements? Does eating carrots improve your vision? Can vitamin E protect you from heart disease?
Vitamins Are Vital to Your Health Vitamins Provide Many Different Functions in the Body Vitamins Are Found in Almost Everything You Eat We Need Enough but Not Too Much of Each Vitamin Some Vitamins Are Soluble in Water and Others Are Soluble in Fat Many B Vitamins Are Essential for Energy Production Thiamin: Important for Nerve Function Riboﬂavin: A Bright Yellow Vitamin Niacin: Deﬁciency Caused an Epidemic of Mental Illness Biotin: Eggs Contain It but Can Block Its Use Pantothenic Acid: Widely Distributed in Food and Widely Used in the Body Vitamin B6 Is Important for Protein Metabolism Vitamin B6 Is Needed to Synthesize and Break Down Amino Acids Both Animal and Plant Foods Are Good Sources of Vitamin B6 Too Much Vitamin B6 Is Toxic Folate and Vitamin B12 Are Needed for Cell Division Folate: Important for Rapidly Dividing Cells Vitamin B12: Absorption Requires Intrinsic Factor Vitamin C Saved Sailors from Scurvy Vitamin C Is Needed to Maintain Connective Tissue Vitamin C Is a Water-Soluble Antioxidant Citrus Fruit Is One of the Best Sources of Vitamin C Vitamin C Is the Most Common Vitamin Supplement Choline: Is It a Vitamin? Vitamin A Is Needed for Healthy Eyes Vitamin A Comes in Preformed and Precursor Forms Vitamin A Requires Fat for Absorption and Protein for Transport Vitamin A Is Necessary for Vision Vitamin A Regulates Gene Expression -Carotene Is a Vitamin A Precursor and an Antioxidant Vitamin A Needs Can Be Met with Plant and Animal Sources Vitamin A Deﬁciency Is a World Health Problem Preformed Vitamin A Can Be Toxic Vitamin D Can Be Made in the Skin Vitamin D Is Needed to Maintain Normal Calcium Levels Vitamin D Deﬁciency Causes Weak Bones Only a Few Foods Are Natural Sources of Vitamin D Too Much Vitamin D Causes Calcium to Deposit in the Wrong Tissues Vitamin E Protects Membranes Vitamin E Is a Fat-Soluble Antioxidant Vitamin E Deﬁciency Damages Membranes Most of the Vitamin E in Our Diets Comes from Plant Oils Vitamin E Is Relatively Nontoxic Vitamin K Is Needed for Blood Clotting Vitamin K Deﬁciency Causes Bleeding Drugs That Inhibit Vitamin K Prevent Fatal Blood Clots The Requirement for Vitamin K Is Met by Bacterial Synthesis and Food Sources
Vitamin D Concerns on the Rise
By Karen Collins, R.D.
Dec. 5, 2003—A lack of vitamin D—thought to be a problem of a bygone era—is showing up in growing numbers of women, children, and the elderly, increasing the risk of bone disease and possibly other health problems. Exposing only the face, hands, and forearms to sunlight for 10 to 30 minutes, just two or three days a week, can usually produce all the vitamin D we need. Longer exposure doesn’t produce more of this vitamin. Yet today, many people’s lifestyles and locations do not allow them to produce enough, making dietary sources vital. For more information on vitamin D concerns go to www.msnbc.msn.com/id/3660416.
ren’t vitamin deﬁciency diseases a thing of the past? After all, the vitamins have been identiﬁed, characterized, and puriﬁed. We get them from...