Are Vegetarians Healthier?

This hardley prooves this is a myth

So what if carotene to vitamin A converts 6 units to 1 and does so in the gut? This doesn't mean that obtaining vitamin A from a plant source is inferior never mind not "entirely obtained from". In fact it turns out this is a good thing, with the gut conversion acting as a safety for overdosing.

The UK GOV website (eatwell.gov.uk) website says that:

"If you do eat liver or liver products every week, you should avoid taking any supplements that contain vitamin A or fish liver oils (which are also high in vitamin A).

Older people should avoid eating liver or liver products more than once a week, or you could eat smaller portions. If you do eat liver products every week, you should also avoid taking any supplements that contain vitamin A or fish liver oils. This is because having too much vitamin A (more than 1.5mg of vitamin A per day from food or supplements), might increase the risk of bone fracture. [If you're pregnant ... ] you should also avoid eating liver and liver products, which includes pâté, because these foods are very high in vitamin A. Having too much vitamin A might harm your unborn baby . For the same reason, you also need to avoid taking supplements containing vitamin A or fish liver oils. Ask your GP or midwife if you want more information."

So it may turn out that you can't overdose on vitamin A plant foods because if you eat a bunch of sweet potatoes all at once your body is not going to be able to convert all that in vitamin A as your gut would be overloaded with material -- where as liver on the other hand is already in vitamin A form and too much could lead to serious health issues.

As for the other argument, just because a small percent of people have a diminished ability of converting carotene -- doesn't prove it a myth. I could cite people who have allergies to meat but I venture to guess you wouldn't find it accurate for me to say that this proves it's a myth that meat is required for optimum health.

In you're argument you say that a sweet potato (containing about 25,000 units of beta-carotene) will only convert into about 4,000 units of vitamin A. "Units" of beta-carotene are ALREADY corrected for the human body's imperfect conversion of this substance to retinol. One International Unit of "vitamin A activity" is set equal to 0.6 micrograms beta-carotene, or 0.3 micrograms of retinol. The reason for this is that the 2:1 ratio is what is required in human feeding trials to raise serum retinol levels by a given amount. The average person who eats 25,000 I.U. of beta carotene gets 25,000 I.U. of vitamin A.

While beta carotene absorption and conversion is less in people with thyroid problems and bile duct obstruction, these illnesses do NOT as a rule result in vitamin A deficiency. Whether they do in vegetarians is not, so far as I can tell, known. Until somebody reports it, it remains a nice
theory. I have been able to find NO studies reporting vitamin A shortages in vegans. Where are they?

Vitamin A is found in animal livers and lactations. All other animal products have essentially zero except except cod fish, salmon and oysters. Not every culture drinks animal milk, not every culture has cod or salmon in their diet and quite frankly I know very few people or cultures who can afford to eat liver regularly -- after all there's only one per animal body. Even if was the case that all meat had vitamin A, the whole "human's evolved eating meat" argument in no way proves a vegetarian diet is not healthier. There's a lot of people who lack the enzyme to digest dairy. People with gut problems like those with Chrones Disease avoid dairy due to the lactose. If I was to argue the way the Weston A Price Foundation does, I'd say this means that we're probably not supposed to get most of our Vitamin A from animals .