 |
| From http://scottberkun.com/essays/35-how-to-give-and-receive-criticism/ |
"Randomized clinical trials designed to investigate the effects of vitamin D intake on bone health have suggested that higher vitamin D intakes may reduce the risk of cancer. One study involved nearly 1,200 healthy postmenopausal women who took daily supplements of calcium (1,400 mg or 1,500 mg) and vitamin D (25 μg vitamin D, or 1,100 IU―a relatively large dose) or a placebo for 4 years. The women who took the supplements had a 60 percent lower overall incidence of cancer (6); however, the study did not include a vitamin D-only group. Moreover, the primary outcome of the study was fracture incidence; it was not designed to measure cancer incidence. This limits the ability to draw conclusions about the effect of vitamin D intake on cancer risk."
1) The women who took the supplements had a 60 percent lower overall incidence of cancer. Yeah, so? The following result was ignored: When analysis was confined to cancers diagnosed after the first 12 mo, RR for the Ca+D group fell to 0.232 (CI: 0.09, 0.60; P<: 0.005). The women who took the supplements had a 77 percent lower overall incidence of cancer, if they didn't already have cancer. Incomplete data dismissed.
2) The study did not include a vitamin D-only group. Yeah, so? It was looking at the effect of Ca+D on cancer risk, not D only. Ca+D greatly reduced cancer risk. Argument dismissed.
3) Moreover, the primary outcome of the study was fracture incidence; it was not designed to measure cancer incidence. Yeah, so? It measured cancer incidence. There's a little clue in the title of the study. Argument dismissed.
4) This limits the ability to draw conclusions about the effect of vitamin D intake on cancer risk. See 1), 2) and 3). Argument dismissed.
Do you get the feeling that someone, somewhere is more interested in collecting loadsa money than trying to reduce cancer risk?
No comments:
Post a Comment