2005 Aug | News You Can Use: Vitamin C aids Lutein, Calcium Fights Polyps, Higher Vitamin D Needs

News You Can Use:
Vitamin C aids Lutein, Calcium Fights Polyps, Higher Vitamin D Needs

Vitamin C Helps Lutein Absorption

Higher intakes of lutein have been linked to a lower risk of developing age-related macular degeneration. Since the levels of lutein associated with eye health are much higher than the amounts we typically get from our diet, many people now take lutein supplements to close that dietary gap. Results from a recent study suggest that it may be better to take supplements of lutein along with vitamin C (1).

To learn whether other antioxidants affect the absorption of lutein from supplements, researchers from the University of Wisconsin gave young healthy men and women supplements of lutein alone, or combined with vitamins C or E. Whether given alone or with one of the vitamins, absorption of lutein varied greatly among individuals. However lutein was absorbed significantly faster when given simultaneously with vitamin C.

Calcium Works Against Polyps

In 1999, Dartmouth Medical School researchers reported that participants in the Calcium Polyp Prevention Study who took calcium supplements lowered their risk of all colorectal cancers by 20%. In that study, 930 adults took either 1200 mg. of supplemental calcium or a placebo over a four-year period. Just recently, the researchers updated their findings on the 822 study participants who continued to be monitored.

More than five years after the original study concluded, the benefits from calcium were even greater than during the treatment phase, with a 41% drop in the risk of polyps and a 35% fall in the risk of all colorectal cancers. The protective effect persisted for up to five years after the group stopped taking supplements, though it didn't last beyond five years. According to lead investigator, there appears to be a delayed and pronounced effect of calcium in suppressing new polyp or tumor formation.

Even though the benefits of calcium seem to be long-lasting for the colon, other studies have reported that gains in bone density from calcium are lost a year or two after stopping supplementation. So remember to take calcium supplements daily for consistent benefits to bone as well as colon health. Taking vitamin D along with calcium is the best bet, since vitamin D also works against colon cancer (2,3).

Vitamin D Recommendations Could Be Too Low

We become less able to absorb vitamin D as we grow older (4). Older individuals also get less of this vitamin from foods and become less efficient at making their own vitamin D from sunlight exposure. These age-related effects led the Institute of Medicine to increase the RDA for vitamin D to 600 IU for elderly people several years ago. Now a new review suggests that even 600 IU may be too low for that age group (5).

The review included 12 double blind trials of vitamin D with and without calcium to determine the effectiveness of the vitamin in preventing fractures of the hip and other bones in older persons. No significant effect of 400 IU vitamin D was seen in the analysis, while 700-800 IU vitamin D daily was found to reduce the risk of hip fracture by 26% in older individuals. It appears that those 60 years and older should aim for at least 700 IU vitamin D daily.