Lecture Notes for IU RDA PDF

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Lecture Notes for IU RDA...

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RDAs for vitamin Aare given as mcg of retinol activity equivalents (RAE) to account for the different bioactivities of retinol and provitamin A carotenoids (see Table 1). Because the body converts all dietary sources of vitamin A into retinol, 1 mcg of physiologically available retinol is equivalent to the following amounts from dietary sources: 1 mcg of retinol, 12 mcg of beta-carotene, and 24 mcg of alpha-carotene or beta-cryptoxanthin. Fromd  ietary supplements, the body converts 2 mcg of beta-carotene to 1 mcg of retinol. Currently, vitamin A is listed on food ands upplementlabels in international units (IUs) even though nutrition scientists rarely use this measure. Conversion rates between mcg RAE and IU are as follows [7] : ● ● ● ●

1 IU retinol = 0.3 mcg RAE 1 IU beta-carotene from dietary supplements = 0.15 mcg RAE 1 IU beta-carotene from food = 0.05 mcg RAE 1 IU alpha-carotene or beta-cryptoxanthin = 0.025 mcg RAE

EXAMPLE: Nature’s made prenatal supplement has 2567IU Vitamin A as Beta Carotene so I need to convert this to RAE. Since 1IU Beta Carotene from supplements = 0.15 mcg RAE I multiply 2567IU x 0.15mcg = 385.05mcg RAE. This is how much my supplement contains.  For a pregnant woman 35 years old the RDA is 770mcg so I divide 385/770 to determine what percent the RDA my supplement has: 385/770 = 50% RDA

RDAs for vitamin Eare provided in milligrams (mg) and are listed in Table 1. Because insufficient data are available to develop RDAs for infants, AIs were developed based on the amount of vitamin E consumed by healthy breastfed babies. At present, the vitamin E content of foods and dietary supplements is listed on labels in international units (IUs), a measure of biological activity rather than quantity. Naturally sourced vitamin E is calledRRR- alpha-tocopherol (commonly labeled asd- alpha-tocopherol); the synthetically produced form isall rac- alpha-tocopherol (commonly labeled asdl- alpha-tocopherol). Conversion rules are as follows: ●

To convert from mg to IU: 1 mg of alpha-tocopherol is equivalent to 1.49 IU of the natural form or 2.22 IU of the synthetic form.

●

To convert from IU to mg: 1 IU of the natural form is equivalent to 0.67 mg of alpha-tocopherol. 1 IU of the synthetic form is equivalent to 0.45 mg of alpha-tocopherol.

RDA for Vitamin D Table 2: Recommended Dietary Allowances (RDAs) for Vitamin D [1] Age

Male

Female

Pregnancy

Lactation

0–12 months*

400 IU (10 mcg)

400 IU  (10 mcg)



1–13 years

600 IU (15 mcg)

600 IU  (15 mcg)



14–18 years

600 IU (15 mcg)

600 IU (15 mcg)

600 IU (15 mcg)

600 IU (15 mcg)

19–50 years

600 IU (15 mcg)

600 IU (15 mcg)

600 IU (15 mcg)

600 IU (15 mcg)

51–70 years

600 IU (15 mcg)

600 IU  (15 mcg)



>70 years

800 IU (20 mcg)

800 IU  (20 mcg)  



RDAs for vitamin D are listed in both International Units (IUs) and micrograms (mcg); the biological activity of 40 IU is equal to 1 mcg

http://blog.naturalhealthyconcepts.com/2014/07/01/excipients-in-supplements/...