Re: Does calcium block zinc absorption?

[Guest guest]

Some sources say yes, some say no. I think iron is more blocked by

calcium than zinc is. If supplements are being taken, you might take

them at different meals and add betaine hydrochloride, and make sure

of taking CLO and getting plenty of good fats to enhance absorption,

and of course avoid grains unless soaked or sprouted. If I remember

correctly, sugar can interfere with calcium absorption (See

Appleton's book), perhaps zinc as well; at least it depletes nutrients

as it's devoid of everything needed to use it.

Jeanmarie

Taking Extra Calcium May Require Added Zin

By Judy McBride

January 20, 1998

Consuming extra calcium from dairy products or supplements could put

older women at risk of low zinc--unless they get extra zinc, too.

That's the word from two studies at the USDA Mayer Human

Nutrition Research Center on Aging at Tufts, Boston. The center is

funded by USDA's Agricultural Research Service.

Zinc's many functions include helping us maintain a healthy immune

system, skin and appetite.

Calcium supplement sales have soared with the growing awareness that

high intakes of this mineral help prevent osteoporosis. Some studies

have found that extra calcium blocks zinc absorption; others haven't.

J. Wood and Jia Ju Zheng looked for a zinc-calcium interaction

in elderly women because, as a group, they tend to have low zinc

intakes. About half of U.S. women consume less than two-thirds the

Recommended Dietary Allowance of 12 mg, according to survey data. And

the amount of zinc people absorb from their meals decreases with age.

In one of the new studies, 18 relatively healthy women past menopause

increased calcium intake to 1,360 milligrams daily--a little higher

than the 1,200 mg now recommended for people over age 50. Their zinc

absorption dropped by an average of about 2 mg, as did zinc balance.

This happened regardless of whether they got the extra calcium from

milk or from a calcium phosphate supplement. The study lasted 36

days. .. . . http://www.ars.usda.gov/IS/pr/1998/980120.htm

Dietary calcium does not exacerbate phytate inhibition of zinc

absorption by women from conventional diets.

Hunt JR, Beiseigel JM.

US Department of Agriculture-Agricultural Research Service, Grand

Forks Human Nutrition Research Center, Grand Forks, ND 58202-9034,

USA. janetrhunt@...

BACKGROUND: Although calcium inhibits zinc bioavailability in rats,

especially from high-phytate diets, the effect of calcium on zinc

absorption by humans from practical diets remains unclear. OBJECTIVE:

The objective was to test the inhibitory effect of dietary calcium, in

Western diets with high and low phytate content, on zinc absorption.

DESIGN: Using a 2 x 2 factorial design, zinc absorption was determined

in 10 healthy women from 1-d diets with moderate and high calcium

contents of approximately 700 and 1800 mg/d and low and high phytate

contents of approximately 440 and 1800 mg/d. Absorption was measured

by using extrinsically added (65)Zn and subsequent whole-body

scintillation counting. RESULTS: Mean (+/-SE) fractional zinc

absorption was 32.8 +/- 2.3% from the moderate-calcium, low-phytate

diet; 26.9 +/- 2.4% from the moderate-calcium, high-phytate diet; 39.4

+/- 2.4% from the high-calcium, low-phytate diet; and 26.2 +/- 2.3%

from the high-calcium, high-phytate diet. The respective values for

absolute zinc absorption were 3.8 +/- 0.3, 3.0 +/- 0.3, 4.5 +/- 0.3,

and 3.2 +/- 0.3 mg/d. Phytate significantly reduced fractional zinc

absorption by approximately 10 percentage points and reduced absolute

zinc absorption by 25%, or approximately 1 mg/d. Differences in

dietary calcium did not affect zinc absorption, regardless of a high

or low dietary phytate content. CONCLUSIONS: In healthy women

consuming 1-d menus of ordinary foods (some fortified with calcium),

dietary phytate reduces zinc absorption, but calcium does not impair

zinc absorption, regardless of whether dietary phytate is low or

high. . . . http://www.ncbi.nlm.nih.gov/pubmed/19176739

On Sep 30, 2009, at 3:51 PM, crayfishfeed wrote:

> My friend who is taking zinc and is concerned about this. I have no

> idea but I know foods in nature contain both. has anyone heard this

> before?

>

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>

[Guest guest]

good info, thanks.

>

> > My friend who is taking zinc and is concerned about this. I have no

> > idea but I know foods in nature contain both. has anyone heard this

> > before?

> >

> >

> >

>

>

>

>