monicapink
11-23-04, 06:18 PM
The information I have presented here is copied verbatim from an article written by Jean Carper titled ....
VITAMIN A IS A BALANCING ACT
TOO MUCH Vitamin A MIGHT PROMOTE cancer, birth defects and bone loss. TOO LITTLE makes you MORE PRONE TO INFECTIONS, VISION PROBLEMS AND -- YES, AGAIN -- BONE LOSS. WHAT'S THE RIGHT DOSE ?
It's confusing to describe, because food and supplements give you two forms of vitamin A: PLANT DERIVED BETA CAROTENE THAT THE BODY CONVERTS INTO VITAMIN A, AND "PREFORMED" ANIMAL-DERIVED RETINOL
Here's the latest on both types:
I. BETA CAROTENE
You CAN'T DEPEND on it for Vitamin A activity. People convert from 0% to at best 11% of beta carotene into Vitamin A, says biochemist Betty Burri of the USDA and the University of California at Davis. MEGADOSES MAY PROMOTE CANCER, NOTABLY IN HEAVY SMOKERS.
BOTTOM LINE:
SMOKERS SHOULDN'T TAKE PURE BETA CAROTENE SUPPLEMENTS, Burri says. ALL OTHERS SHOULD AVOID HIGH DOSES (30 milligrams or more daily) EXCEPT ON THE ADVICE OF A HEALTH PROFESSIONAL. INSTEAD EAT FRUITS AND VEGETABLES, ESPECIALLY CARROTS, SPINACH AND SWEET POTATOES. CHOP OR MASH THEM AND ADD A LITTLE FAT TO UP THE ODDS OF ABSORPTION.
II. RETINOL
TOO MUCH IS TOXIC, HARMS THE LIVER AND MAY PROMOTE BIRTH DEFECTS. WHETHER IT WEAKENS BONES IS A NEW CONTROVERSY. In a Harvard study, getting more than 10,000 IU of Vitamin A DAILY (as from liver, milk and supplements) HIKED FRACTURE RISK 48% IN OLDER WOMEN, prompting advice to limit supplements to 5,000 IU daily. HOWEVER, two recent studies DID NOT FIND A LINK BETWEEN HIGH INTAKE OF VITAMIN A AND LOWER BONE MINERAL DENSITY or INCREASED FRACTURES IN OLDER WOMEN.
BOTTOM LINE:
RESTRICT INTAKE TO 10,000 IU DAILY, the upper "SAFE" LIMIT set by the Institute of Medicine. [COLOR=Red]BEWARE OF LIVER: EATING JUST 1 OUNCE BRINGS YOU TO THE LIMIT.
VITAMIN A IS A BALANCING ACT
TOO MUCH Vitamin A MIGHT PROMOTE cancer, birth defects and bone loss. TOO LITTLE makes you MORE PRONE TO INFECTIONS, VISION PROBLEMS AND -- YES, AGAIN -- BONE LOSS. WHAT'S THE RIGHT DOSE ?
It's confusing to describe, because food and supplements give you two forms of vitamin A: PLANT DERIVED BETA CAROTENE THAT THE BODY CONVERTS INTO VITAMIN A, AND "PREFORMED" ANIMAL-DERIVED RETINOL
Here's the latest on both types:
I. BETA CAROTENE
You CAN'T DEPEND on it for Vitamin A activity. People convert from 0% to at best 11% of beta carotene into Vitamin A, says biochemist Betty Burri of the USDA and the University of California at Davis. MEGADOSES MAY PROMOTE CANCER, NOTABLY IN HEAVY SMOKERS.
BOTTOM LINE:
SMOKERS SHOULDN'T TAKE PURE BETA CAROTENE SUPPLEMENTS, Burri says. ALL OTHERS SHOULD AVOID HIGH DOSES (30 milligrams or more daily) EXCEPT ON THE ADVICE OF A HEALTH PROFESSIONAL. INSTEAD EAT FRUITS AND VEGETABLES, ESPECIALLY CARROTS, SPINACH AND SWEET POTATOES. CHOP OR MASH THEM AND ADD A LITTLE FAT TO UP THE ODDS OF ABSORPTION.
II. RETINOL
TOO MUCH IS TOXIC, HARMS THE LIVER AND MAY PROMOTE BIRTH DEFECTS. WHETHER IT WEAKENS BONES IS A NEW CONTROVERSY. In a Harvard study, getting more than 10,000 IU of Vitamin A DAILY (as from liver, milk and supplements) HIKED FRACTURE RISK 48% IN OLDER WOMEN, prompting advice to limit supplements to 5,000 IU daily. HOWEVER, two recent studies DID NOT FIND A LINK BETWEEN HIGH INTAKE OF VITAMIN A AND LOWER BONE MINERAL DENSITY or INCREASED FRACTURES IN OLDER WOMEN.
BOTTOM LINE:
RESTRICT INTAKE TO 10,000 IU DAILY, the upper "SAFE" LIMIT set by the Institute of Medicine. [COLOR=Red]BEWARE OF LIVER: EATING JUST 1 OUNCE BRINGS YOU TO THE LIMIT.