Dietary Reference Intakes The Essential Guide to Nutrient Requirements (2006) / Chapter Skim
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From page 262... ...
TABLE 1 Dietary Reference Intakes for Niacin by Life Stage Group DRI values (mg/day) EARa,b RDAa,c AIa,d ULe,f males females males females Life stage group NDg 0 through 6 mo 2 7 through 12 mo 4 ND 1 through 3 y 5 5 6 6 10 4 through 8 y 6 6 8 8 15 9 through 13 y 9 9 12 12 20 14 through 18 y 12 11 16 14 30 19 through 30 y 12 11 16 14 35 31 through 50 y 12 11 16 14 35 51 through 70 y 12 11 16 14 35 > 70 y 12 11 16 14 35 Pregnancy £ 18 y 14 18 30 19 through 50 y 14 18 35 Lactation £ 18 y 13 17 30 19 through 50 y 13 17 35 a As niacin equivalents (NE)
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From page 263... ...
PART III: NIACIN 263 NIACIN T he term niacin refers to nicotinamide (nicotinic acid amide) , nicotinic acid (pyridine-3-carboxylic acid)
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From page 264... ...
DRIs: THE ESSENTIAL GUIDE TO NUTRIENT REQUIREMENTS 264 Absorption, Metabolism, Storage, and Excretion Absorption of niacin from the stomach and intestine is rapid. At low concentra tions, absorption is mediated by sodium ion–dependent facilitated diffusion.
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From page 265... ...
PART III: NIACIN 265 Lactation £ 18 y through 50 y Age-specific requirement + energy expenditure of human milk production The UL The Tolerable Upper Intake Level (UL) is the highest level of daily nutrient intake that is likely to pose no risk of adverse effects for almost all people.
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From page 266... ...
DRIs: THE ESSENTIAL GUIDE TO NUTRIENT REQUIREMENTS 266 vey (1981–1984) , median supplemental niacin intakes were 20 mg/day for men and 30 mg/day for women.
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From page 267... ...
PART III: NIACIN 267 associated with chronic alcoholism and in individuals with conditions that disrupt the metabolism of tryptophan. Deficiencies of other micronutrients, such as pyridoxine and iron, which are required to convert tryptophan to niacin, may also contribute to the appearance of pellagra.
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From page 268... ...
DRIs: THE ESSENTIAL GUIDE TO NUTRIENT REQUIREMENTS 268 KEY POINTS FOR NIACIN Niacin is involved in many biological reactions, including 3 intracellular respiration and fatty acid synthesis. The amino acid tryptophan is converted in part into nicotinamide and thus can contribute to meeting the requirement for niacin.
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From page 269... ...
PART III: NIACIN 269 There is no evidence of adverse effects associated with the 3 excess consumption of naturally occurring niacin in foods. But adverse effects may result from excess niacin intake from dietary supplements, pharmaceutical preparations, and fortified foods.
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