Bottom Line: Vitamin C is easily absorbed�your body doesn't need any help. In any case, you can't tell what substances, and how much, are in rose hip "extracts." There may be little or none of them in vitamin C pills labeled "with rose hips." There's no evidence that rose hips help your body absorb vitamin C. This is just a more expensive source of C.

Full Article, Wellness Letter, March 1996:

Rose hips: worth the price?

If you've ever bought vitamin C supplements (the WELLNESS LETTER recommends 250 to 500 milligrams a day), you've probably wondered about rose hips, which are listed on the labels of many C pills. Today you'll find rose hips also in teas, capsules, liquid extracts, and jellies. Should you be hip to rose hips? Should you pay up to 10 times more to get your C from rose hips than from synthetic C pills?

Only if you have money to burn. Rose hips, the red fruit of various rose species, are indeed a concentrated natural source of vitamin C. They became popular during World War II, when the British, who couldn't import citrus fruits, depended on rose hips, which they made into a syrup, to supply vitamin C and prevent scurvy. Three ounces of fresh rose hips can supply as much as 1,700 milligrams of C, depending on the source of the rose hips and how they've been handled and processed. But there's no way to know how much rose-hip extract is in vitamin C pills and how much C it provides�probably not much. The labels typically state "500 milligrams plus rose hips," which is pretty vague. A 500-milligram vitamin C capsule made solely from rose hips would be quite a horse pill.

What about other nutrients in rose hips? Like citrus fruits, rose hips probably contain other beneficial phytochemicals (such as bioflavonoids). First of all, no one knows exactly what most of these are. Second, no one knows how much of these mystery substances gets into rose hip "extracts." Little or none of them would make it into vitamin C pills. There's no evidence that these other substances help your body absorb vitamin C, despite the claims. In any case, C is easily absorbed�your body doesn't need any help.

Natural vs. synthetic vitamins

"Natural" doesn't mean much when it comes to vitamins. Often companies add a small amount of plant extract, such as rose hips, to synthetic vitamins and then call them natural. (Though supplement makers would like you to believe otherwise, they all buy their raw vitamins and minerals from the same handful of giant manufacturers.) Even if you found C pills that got all of the vitamin from rose hips, they wouldn't be better than the cheapest synthetic C pills. Synthetic vitamins, made in a lab, are identical to the vitamins found in foods. The body can't tell the difference. The only real difference is price.