Does High Calcium Intake Deplete Zinc?

There have been a couple of posts recently along the lines that "the Peat diet" was low in zinc and that high calcium intake would deplete zinc.

So I decided to check what information I could find about it. My conclusion:

A diet that contains adequate animal proteins from milk, eggs, and occasional liver and seafood provides adequate amounts of highly bio-available zinc. High dietary calcium intake does not interfere with zinc utilization.

++++

Bioavailability

"The amount of protein in the diet is a factor contributing to the efficiency of zinc absorption as zinc binds to protein. Small changes in protein digestion may produce significant changes in zinc absorption (Sandstrom & Lonnerdal 1989)."

"In general, zinc absorption from a diet high in animal protein will be greater than from a diet rich in plant derived proteins (King & Keen 1999). The requirement for dietary zinc may be as much as 50% greater for vegetarians, particularly strict vegetarians whose major staples are grains and legumes and whose dietary phytate:zinc ratio exceeds 15:1."

"Current data suggest that consumption of calcium-rich diets does not have a major effect on zinc absorption at an adequate intake level."

Nutrient Reference Values for Australia and New Zealand


"It is recognized that zinc is well absorbed from milk."

Effect of citrate on zinc bioavailability from milk, milk fractions and infant formulas

+++++

Now a few studies...

There have been several "animal studies that have shown that calcium interferes with the intestinal absorption of zinc. Some human studies have shown that increased calcium intake decreases zinc absorption (7, 8), others have been unable to confirm this (9, 10)."

"Wood and Hanssen (7) showed that milk and lactose-free milk reduced zinc absorption in lactose-tolerant and lactoseintolerant postmenopausal women significantly; however, 2 y later, in a subsequent study among postmenopausal women, they were not able to show any significant effect of the addition of milk or a calcium phosphate supplement on either zinc absorption or retention (10)."

I did not check the animal studies. It was mentioned in on of the humans studies that the calcium doses were very high. I am going to discuss reference 8 below.

Zinc balance in adolescent females consuming a low or high calcium diet

This is the most interesting study. It compared a low calcium diet (~ 670 mg) with a high calcium diet (~ 1670 mg). Zinc intake was below RDI.

"As part of the long-term supplementation trial, subjects consumed their normal, self-selected diets and were randomly assigned to receive either placebo tablets or 1000 mg Ca/d as calcium citrate malate."

"Average consumption of calcium was 667 ± 28 mg/d (range: 595-722 mg/d, depending on the amount of food eaten) and of zinc was 5.5 ± 0.6 mg/d (range: 4.4-6.3 mg/d)."

RDI zinc for adolescent females:

US: 9 mg
Australia: 7 mg

The cautious conclusion was that "long-term calcium supplementation with 1000 mg Ca as calcium citrate malate, in addition to dietary calcium, does not have detrimental effects on the zinc balance of adolescent females already consuming low amounts of zinc."

The authors write, "One girl in the supplemented group and four girls in the placebo group were in negative zinc balance. However, no significant difference was found between the placebo and supplemented groups for zinc balance (Table 2)."

However the data in table 2 suggest that calcium supplemented group had a much better zinc balance (0.8 vs 0.3).




The effect of calcium carbonate and calcium citrate on the absorption of zinc in healthy female subjects.

This study is the above mentioned reference 8.

Here the subjects drank water with "either 4.5 mg elemental zinc, zinc with 600 mg elemental calcium as calcium carbonate or zinc with 600 mg elemental calcium as calcium citrate."

If you check food databases, you will find that 600 mg is the average amount of calcium you get from food when you eat a mixed diet containing 4.5 mg zinc.

RESULTS:

"The area under the plasma zinc curve (AUC) (mean +/- SEM) following the coingestion of zinc with calcium carbonate (438.4 +/- 129.0 mumol Zn.min/100 g albumin) and calcium citrate (308.0 +/- 110.5) was significantly lower (P < 0.017) than when zinc was ingested alone (1561.7 +/- 240). Urinary excretion of calcium was significantly higher (P < 0.017) at 4 h after supplementation with calcium citrate (0.83 +/- 0.12 mumol Ca/mumol creatinine) compared with calcium carbonate (0.40 +/- 0.11)."

The authors come to the conclusion that the result "suggests that an antagonistic competition occurred between the minerals and that elemental calcium is the inhibiting factor."

So this is: zinc alone vs. zinc+calcium. I don't know of a food that does not contain calcium.


Comparisons of the effects of calcium carbonate and calcium acetate on zinc tolerance test in hemodialysis patients.

The effect of "calcium carbonate (CaCO3) and calcium acetate (CaAc), two other phosphate binders, on intestinal Zn absorption in nine patients on hemodialysis and in 11 controls by measuring 1- and 2-hour serum Zn levels after oral administration of 50 mg of elemental Zn as Zn gluconate with or without concomitant administration of 2 g CaCO3 (800 mg elemental Ca) or 3 g CaAc (750 mg elemental Ca)" was studied.

"The results demonstrate that intestinal Zn absorption after an oral Zn challenge decreased in patients on hemodialysis and concomitant administration of CaAc, but CaCO3 did not decrease intestinal Zn absorption in either group."

Unfortunately I could only find the abstract, which does not name numbers only a p-value (aka: plague in science), so we don't know how small or big the effect of CaAc was.


Effect of Dietary Calcium and Phosphorus Levels on the Utilization of Iron, Copper, and Zinc by Adult Males

"Iron, copper, and zinc utilization were examined in nine adult males fed a moderate calcium-moderate phosphorus diet (MCaMP), a moderate calcium-high phosphorus diet (MCaHP), and a high calcium-high phosphorus diets (HCaHP) during a 39-day balance study. The moderate and high calcium diets contained 780 mg and 2382 mg calcium daily, respectively. The moderate and high phosphorus diets contained 843 and 2442 mg phosphorus daily, respectively. The calcium supplements were fed as calcium gluconate, while the phosphorus supplements were fed as glycerol phosphate."

"Dietary treatments had no effect on subjects' fecal and urinary losses of zinc nor on their apparent retention of zinc. Plasma iron, zinc, copper, and transferrin levels and serum ferritin levels were not affected by the dietary treatment."

Thought I would add a bit to this. I found a bit info. on this topic in the discussions section of a study. The study shows that milk enhances zinc absorption from non animal sources. The paper also mentions that meats in general enhance zinc absorption. While I knew about this in regards to iron, I did not know meat could increase zinc absorption as well. Lastly, and of importance to myself at least, milk enhanced zinc absorption (like meat) but had no effect on iron (unlike meat). Here is a snippet from the article:::

Similar to the effect on iron absorption, animal proteins counteract the inhibitory effect of phytate on zinc absorption from single meals (36); however, the specific effect of milk on zinc absorption is somewhat controversial. Initial studies suggesting that calcium in milk could reduce zinc absorption (37,38) were made using high amounts of calcium as mineral supplements. More recent studies (31,39–41) found no effect of calcium addition to foods on the absorption of Zn. One study (42) compared zinc absorption between cow’s milk and infant formulas and suggested that casein in milk had a negative effect on zinc absorption compared with whey protein, which is adjusted in infant formula. Although calcium and casein were suggested to be potential inhibitors of zinc absorption, no studies have addressed the effect of milk addition on zinc absorption from a meal based on plant foods in which zinc absorption is already inhibited. We found that zinc absorption increased significantly in subjects consuming milk and yogurt added to such meals by 50 and 68% respectively. The total amount of zinc absorbed was also increased by 70 and 78% with milk and yogurt, respectively, compared with the control meal alone. We found that milk and yogurt counteracted the inhibitory effect of phytate on zinc absorption from single meals as was found for other animal proteins (36). This effect was attributed to the amino acids released from the protein that keep the zinc in solution (38). The exact mechanism for a positive effect of milk and yogurt on zinc absorption, as with other animal proteins, remains to be elucidated.

It may be that milk has an indirect effect on zinc absorption by somehow counter-acting phytic acid. It would be nice if it enhanced zinc absorption directly as that would mean the zinc naturally in milk would be well absorbed. I haven't looked that far into this yet, so I don't know, but I will try to find as much information as I can and post it.

I suspect one way that milk could enhance the zinc in vegetable foods is by binding of the calcium in the milk to the phytic acid in the vegetable foods, leaving zinc unbound. I'm not sure if this actually makes sense as I don't know much about the topic. Hopefully other people can provide more useful information.

"The present study suggests that milk and yogurt when added to a plant-based meal significantly increase zinc absorption and did not affect iron absorption. The exact mechanism producing these effects requires further study."

The Addition of Milk or Yogurt to a Plant-Based Diet Increases Zinc Bioavailability but Does Not Affect Iron Bioavailability in Women

Excellent post!
Lately, I was reading " zinc in human biology " and came across the following explanation regarding zinc and calcium ions that I never heard or read anywhere before:

"The zinc ion with its 10 outer electrons in d orbital forms a tetrahedral Sp3 chelate configuration and prefers a coordination number of four. These parameters are identical to those for Cu+ and Cd2 + and therefore these elements would be expected to interact with zinc. Such biological interactions between zinc and copper or cadmium have been well documented. An element such as calcium with its filled 3p orbital, forming an octahedral d2sp3 chelate configuration, therefore preferring a coordination number of six, would not be expected to interact with zinc.
.....Of the cations in the human diet, calcium is present in the highest concentrations. Although calcium is thought to have its own closely regulated uptake mechanism, animal studies have shown that high calcium levels can impair the intestinal absorption of zinc (Heth and Hoekstra 1965). However, metabolic balance studies in human subjects offered calcium intakes of 200, 800 and 2000 mg/d (the two higher levels achieved by addition of calcium gluconate) did not show any effect of calcium level on zinc absorption or balance (Spencer et al. 1984). Neither 500 mg of elemental calcium as calcium carbonate or hydroxyapatite added to a standard test meal containing 3.62 mg of zinc (Dawson-Hughes et al. 1986) nor addition of calcium (as calcium chloride) to a cows' milk infant formula to simulate the levels of calcium found in cows' milk (Uinnerdal et al. 1984) altered the absorption of 65Zn. Thus, there are no indications that calcium per se impairs zinc absorption at levels found in human diets. "

Giraffe said:

There have been a couple of posts recently along the lines that "the Peat diet" was low in zinc and that high calcium intake would deplete zinc.

So I decided to check what information I could find about it. My conclusion:

A diet that contains adequate animal proteins from milk, eggs, and occasional liver and seafood provides adequate amounts of highly bio-available zinc. High dietary calcium intake does not interfere with zinc utilization.

++++

Bioavailability

"The amount of protein in the diet is a factor contributing to the efficiency of zinc absorption as zinc binds to protein. Small changes in protein digestion may produce significant changes in zinc absorption (Sandstrom & Lonnerdal 1989)."

"In general, zinc absorption from a diet high in animal protein will be greater than from a diet rich in plant derived proteins (King & Keen 1999). The requirement for dietary zinc may be as much as 50% greater for vegetarians, particularly strict vegetarians whose major staples are grains and legumes and whose dietary phytate:zinc ratio exceeds 15:1."

"Current data suggest that consumption of calcium-rich diets does not have a major effect on zinc absorption at an adequate intake level."

Nutrient Reference Values for Australia and New Zealand


"It is recognized that zinc is well absorbed from milk."

Effect of citrate on zinc bioavailability from milk, milk fractions and infant formulas

+++++

Now a few studies...

There have been several "animal studies that have shown that calcium interferes with the intestinal absorption of zinc. Some human studies have shown that increased calcium intake decreases zinc absorption (7, 8), others have been unable to confirm this (9, 10)."

"Wood and Hanssen (7) showed that milk and lactose-free milk reduced zinc absorption in lactose-tolerant and lactoseintolerant postmenopausal women significantly; however, 2 y later, in a subsequent study among postmenopausal women, they were not able to show any significant effect of the addition of milk or a calcium phosphate supplement on either zinc absorption or retention (10)."

I did not check the animal studies. It was mentioned in on of the humans studies that the calcium doses were very high. I am going to discuss reference 8 below.

Zinc balance in adolescent females consuming a low or high calcium diet

This is the most interesting study. It compared a low calcium diet (~ 670 mg) with a high calcium diet (~ 1670 mg). Zinc intake was below RDI.

"As part of the long-term supplementation trial, subjects consumed their normal, self-selected diets and were randomly assigned to receive either placebo tablets or 1000 mg Ca/d as calcium citrate malate."

"Average consumption of calcium was 667 ± 28 mg/d (range: 595-722 mg/d, depending on the amount of food eaten) and of zinc was 5.5 ± 0.6 mg/d (range: 4.4-6.3 mg/d)."

RDI zinc for adolescent females:

US: 9 mg
Australia: 7 mg

The cautious conclusion was that "long-term calcium supplementation with 1000 mg Ca as calcium citrate malate, in addition to dietary calcium, does not have detrimental effects on the zinc balance of adolescent females already consuming low amounts of zinc."

The authors write, "One girl in the supplemented group and four girls in the placebo group were in negative zinc balance. However, no significant difference was found between the placebo and supplemented groups for zinc balance (Table 2)."

However the data in table 2 suggest that calcium supplemented group had a much better zinc balance (0.8 vs 0.3).

View attachment 1869


The effect of calcium carbonate and calcium citrate on the absorption of zinc in healthy female subjects.

This study is the above mentioned reference 8.

Here the subjects drank water with "either 4.5 mg elemental zinc, zinc with 600 mg elemental calcium as calcium carbonate or zinc with 600 mg elemental calcium as calcium citrate."

If you check food databases, you will find that 600 mg is the average amount of calcium you get from food when you eat a mixed diet containing 4.5 mg zinc.

RESULTS:

"The area under the plasma zinc curve (AUC) (mean +/- SEM) following the coingestion of zinc with calcium carbonate (438.4 +/- 129.0 mumol Zn.min/100 g albumin) and calcium citrate (308.0 +/- 110.5) was significantly lower (P < 0.017) than when zinc was ingested alone (1561.7 +/- 240). Urinary excretion of calcium was significantly higher (P < 0.017) at 4 h after supplementation with calcium citrate (0.83 +/- 0.12 mumol Ca/mumol creatinine) compared with calcium carbonate (0.40 +/- 0.11)."

The authors come to the conclusion that the result "suggests that an antagonistic competition occurred between the minerals and that elemental calcium is the inhibiting factor."

So this is: zinc alone vs. zinc+calcium. I don't know of a food that does not contain calcium.


Comparisons of the effects of calcium carbonate and calcium acetate on zinc tolerance test in hemodialysis patients.

The effect of "calcium carbonate (CaCO3) and calcium acetate (CaAc), two other phosphate binders, on intestinal Zn absorption in nine patients on hemodialysis and in 11 controls by measuring 1- and 2-hour serum Zn levels after oral administration of 50 mg of elemental Zn as Zn gluconate with or without concomitant administration of 2 g CaCO3 (800 mg elemental Ca) or 3 g CaAc (750 mg elemental Ca)" was studied.

"The results demonstrate that intestinal Zn absorption after an oral Zn challenge decreased in patients on hemodialysis and concomitant administration of CaAc, but CaCO3 did not decrease intestinal Zn absorption in either group."

Unfortunately I could only find the abstract, which does not name numbers only a p-value (aka: plague in science), so we don't know how small or big the effect of CaAc was.


Effect of Dietary Calcium and Phosphorus Levels on the Utilization of Iron, Copper, and Zinc by Adult Males

"Iron, copper, and zinc utilization were examined in nine adult males fed a moderate calcium-moderate phosphorus diet (MCaMP), a moderate calcium-high phosphorus diet (MCaHP), and a high calcium-high phosphorus diets (HCaHP) during a 39-day balance study. The moderate and high calcium diets contained 780 mg and 2382 mg calcium daily, respectively. The moderate and high phosphorus diets contained 843 and 2442 mg phosphorus daily, respectively. The calcium supplements were fed as calcium gluconate, while the phosphorus supplements were fed as glycerol phosphate."

"Dietary treatments had no effect on subjects' fecal and urinary losses of zinc nor on their apparent retention of zinc. Plasma iron, zinc, copper, and transferrin levels and serum ferritin levels were not affected by the dietary treatment."

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if it doesnt deplete zinc, do you have any other findings that showed what did deplete zinc? nice post here btw.. lots of good research.

mayweatherking said:

if it doesnt deplete zinc, do you have any other findings that showed what did deplete zinc?

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You should also inform about chelation by polyphenols, especially iron. Chelation of divalent cations Cu (II) and Zn (II) is low. The basic cations (Ca K Mg) are not chelated.
The phenol group is a strong ligand: it promotes interaction with cations / high density metals, such as for example the iron (III), copper (II) and zinc (II). In general the attraction for the trivalent cations is stronger than for divalent cations. That's why polyphenols will also link to aluminum (III). Polyphenols do not chelate the basic cations such as sodium, potassium and calcium. There may be a low interaction with magnesium, but in the presence of phosphate (milk) the catechol function will lose / release magnesium ions.
Sources :
1. http://vin-ou-raisin.e-monsite.com/pages/effets-benefiques-des-polyphenols/activites-antioxydantes-des-polyphenols.html
2. Flavonoids and other polyphenols. Lester Packer. Elsevier. (Ph. Dr) (dead link)

NB : We could also get interaction with metabolism when taking polyphenols supplements (resveratrols) through TSH increased secretion. Anything with phenols will interfere with mitochondrial respiration.

People on thyroid medication do not often produce enough of the thyroid hormones triiodothyronine (T3). Depending on their levels of each of these hormones (T3 and T4), as well as the presence of thyroid-stimulating hormone (TSH), we should reconsider the use of polyphenols from supplements.
As you know, there is an interaction between calcium and TSH levels. Not enough Ca will raise TSH and will excite the body. Too much calcium, from supplement, without adequate K2, will cause more problems than to solve a situation (muscle and artery calcification). There is also a strong interaction between liposoluble vitamins A D K.
Interesting links (in French, with English source)
http://mirzoune-ciboulette.forumactif.org/t655-interaction-entre-pth-la-vitamine-d3-et-le-calcium#5832
http://mirzoune-ciboulette.forumactif.org/t127-interaction-entre-les-vitamines-liposolubles#890

Tenacity said:

Apparently there's a protein in human milk that enhances zinc absorption, but it's not as present (or not present at all) in cow's milk. Curious about this one too, as it's made me reconsider my low-meat and a quart of milk a day habit.

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I think you are referring to zinc-binding ligand. I will have to confirm this, but I think that ZBL is indeed present in human milk and not really in cows milk, like you said, but I think that it is present in the mucosal lining of the intestine in adults, whereas it is absent in infants (so infants drinking cows milk would not be absorbing as much zinc? This is relevant to formula fed infants). Anyway, I think I will research the whole calcium + zinc thing further so that we can get to the bottom of this as I drink a lot of milk and don't always back up my nutrition with oysters and red meat. I will write a follow-up post later.

schultz said:

I think you are referring to zinc-binding ligand. I will have to confirm this, but I think that ZBL is indeed present in human milk and not really in cows milk, like you said, but I think that it is present in the mucosal lining of the intestine in adults, whereas it is absent in infants (so infants drinking cows milk would not be absorbing as much zinc? This is relevant to formula fed infants). Anyway, I think I will research the whole calcium + zinc thing further so that we can get to the bottom of this as I drink a lot of milk and don't always back up my nutrition with oysters and red meat. I will write a follow-up post later.

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Thank you!