T Nation

Milk Leaches Calcium From Bones?!


#1

One of my teachers (a knowledgeable guy, not trying to sabotage etc.) has just informed me that drinking too much milk 'leaches calcium from your bones'. He says he's not completely sure if it's just an old wive's tale, but there seems to be some interesting information around the net.

Now let it be clear that I love my milk, and for a while I was on GOMAD (didn't go down too well with the boarding house as I very quickly ran out the supply :D), but I want some objective, non-biased information about this! I've never heard it before so I can't help but feel that it may only be in vast quantities, but still...?

Thoughts?


#2

I know the answer to this once. A quick google will probably tell you.

There's something that's either injected or used in cheap feed that contains substance "x" (forgetting the name), which your body treats like calcium.

As such, the same thing always happens whenever you trick your body into thinking it's eating y when it's eating x: the absorption rate of y goes down. Calcium is something you constantly need. So when you adsorb this stuff, it makes its way into your bones, and helps prevent/slowdown further calcium absorption.

This is not the product of milk, but the result of ether a drug, or or the way to feed is treated.

Drink milk from a good animal and you're fine.


#3

in one country i think it was sweden im not sure . they discovered that they had a very high incidents of osteoporosis even though they have a relativly healthy diet and drank alot of milk . what they discovered was that the majority of milk had added vitamins amongst them vit A and they realised that this inhibits absorbtion of calcium .


#4

Adding retinol to either supplements or food is an outcome of ignorance.

Vitamin A should be supplied only as beta carotene.

Unfortunately, ignorance is more widespread than it ought to be.


#5

Since retinol needs to be converted, and Beta carotene does not. I assume that is your reasoning, correct Bill?


#6

Actually, the opposite.

Retinol is the active form and so it was reasonable enough, before data came out quite some while ago, to figure that supplying the active form could be the best way to supplement Vitamin A.

Now it was known for a very long time that retinol could be toxic, even enough to kill a person, at very high doses such as what results, for example, from eating the liver of a polar bear.

And it was known that when retinol or derivatives were used at relatively high doses medically -- for example Accutane is a retinol derivative -- there were toxicity problems.

Of course that wouldn't prove a problem with lower dose use.

But some years back (I don't now have the specific reference) a very large study found that supplementation with Vitamin A, as retinol, at common doses correlated with DECREASED life expectancy. This is the only type of vitamin supplementation shown to have such an effect. The effect was both statistically significant and substantial at doses of only 5000 IU/day.

Many companies selling vitamins pulled retinol and its derivatives from their products after this.

Beta carotene does not have this effect, but at for example 5000 IU/day fully supplies the body with what it needs to produce enough Vitamin A itself. Any excess simply goes towards adding an orange hue to the skin, basically.

Supplementation with retinol can readily and often does result in levels that are excessive, if defining an on-average effect of decreasing lifespan to be "excessive."

Now there is newer data as well on adverse effect of retinol supplementation on absorption of calcium.


#7

I hadn't concerned myself with the milk before this thread, as I'm not a big milk drinker anyway though lately I've been going through some.

But I now see that what I have currently is overloaded.

Vitamin A is provided as Vitamin A palmitate, which is retinol palmitate.

And it has 10% RDA (which I think should mean 300 IU) per cup, or therefore 4800 IU of retinol per gallon.

If I were getting no retinol from any other source that would be twice as much as I'd considerable reasonable. If already getting a reasonable amount of retinol, then this would all be over the top.