4 ms·

Sorry guys, don't get excited yet. Bad, misleading headline. What? "Subjects were randomly assigned to take daily dosages of 1,400-1,500 mg supplemental calc

Sorry guys, don't get excited yet. Bad, misleading headline. What? "Subjects were randomly assigned to take daily dosages of 1,400-1,500 mg supplemental calcium, 1,400-1,500 mg supplemental calcium plus 1,100 IU of vitamin D3, or placebos." It's not vitamin D. It may be vitamin D or it may be vitamin D + calcium. Why didn't they have a group that was supplementing only vitamin D and not calcium? I don't know, but since they didn't test that, there's no way to know that it is just vitamin D. Who? "The four-year, randomized study followed 1,179 healthy, postmenopausal women from rural eastern Nebraska." Given the age, male-female ratio on HN, it's not clear that vitamin D supplementation would be beneficial to the average HN reader. Also, all the women were 55 and older. Besides that, as the article mentions, skin color and other genetic heritage also matters. If you are a woman and Caucasian, this study is more likely to apply to you; if you aren't, who knows? In case someone considers going out and supplementing with both calcium and vitamin D on account of this study, I want to point out that unnecessary calcium supplementation can be detrimental, and it can contribute to things like stress, poor sleep, and prostate cancer (if you have one).

timr 17y ago
"It's not vitamin D. It may be vitamin D or it may be vitamin D + calcium. Why didn't they have a group that was supplementing only vitamin D and not calcium? I don't know, but since they didn't test that, there's no way to know that it is just vitamin D." The first rule of scientific criticism is: always read the paper. The classic clinical manifestation of a Vitamin D deficiency is rickets -- the direct consequence of a calcium deficiency. This is because vitamin D is a known enhancer of calcium absorption from the intestine. All other benefits are hypothetical. In light of this information, the researchers controlled for the variability of dietary calcium across participants in the study; they chose to supplement calcium for everyone up to the highest US RDA value. Does that mean that it might be the combination of calcium + vitamin D that conveys the greatest benefit? Well, yes, in fact, that turns out to be true. But since it's trivially easy to supplement calcium and vitamin D simultaneously (and nearly every vitamin D supplement that you can buy includes a calcium supplement), clinically speaking, it makes no difference. But most importantly, the title of the original paper is "Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial." (http://www.ncbi.nlm.nih.gov/pubmed/17556697?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum http://www.ncbi.nlm.nih.gov/pubmed/17556697?ordinalpos=1&#38...), suggesting that the authors are well aware of the relationship between the substances, and are actually interested in the combined effect of calcium and vitamin D. They wanted to know if calcium + vitamin D had a greater cancer-reducing effect than calcium alone, and found that it did. As for your other critiques, the authors state right there in the abstract of the paper that the results are for postmenopausal women in Nebraska, and they don't try to overgeneralize. But since the relationship between vitamin D and calcium are the same for men and women, it's really not unreasonable to suggest that the results could apply more generally -- even if you had to adjust the nutrient levels to fit the age, sex and location of the patient.
- jimmybot 17y ago
  Wha...? Wait a second. The title for the link submitted is: Vitamin D slashes risk of cancers by 77 percent (2007) If what you're saying is true, that calcium + vitamin D confers the greatest benefit, then the link title is still wrong. But what in the study says that calcium + vitamin D conveys the greatest benefit? (ie Vitamin D alone wouldn't convey as great a benefit) It may be true, but it's not obvious from the article that was linked, and it's still not obvious from the original paper that you linked to. The article and you are assuming that what is having the anti-cancer effect is the calcium, and the vitamin D helps you absorb the calcium, thus enhancing that effect. First, I don't assume what you do, which is that supplementing calcium is always a positive. Second, what if vitamin D has some action other than help you absorb calcium. Even if I'm not an expert in this, I find it hard to believe that medical researchers have completely precluded vitamin D from having any action other than help your body absorb calcium, and if it alone helped prevent cancer, it may be really nice to know, especially if you don't want to be increasing your calcium. I don't get the attitude. I was talking about the information was provided by the article. There may very well be a study about men 20-40 years old, of varying ethnic backgrounds, who take just vitamin D (no calcium) and it's found to decrease cancer versus control, but that's not the information provided here by the article or the original study. Your point about actual vitamin D supplements on the market mostly coming with calcium suffers from the same logical problem. The article headline (original or on HN) should tell me what exactly is decreasing the cancer risk, not some assumption about what consumers will end up buying and what they'll likely also end up supplementing with additionally. If the conclusion had been vitamin D alone decreases the risk of cancer, do you think there wouldn't be manufacturers churning out pure vitamin D, without the calcium? EDIT: Okay, parent has updated post. I appreciate that you softened your tone. Sure, I know it says that they aren't sure of the generality of the study in the article. I think it's worth pointing out because again, there's that disconnect between the title and the content. Title says "TAKE VITAMIN D" without qualification. Article says different. Responding to your new point about the generality of the study--if the requirements for men and women really are the same (I don't buy it), then why study post-menopausal white women in Nebraska? I can see age for the cancer risk, but why not men, and why not of different ethnicities? If you're going to tell me that post-menopausal white women 55 and older are more likely to be deficient in calcium and vitamin D, then well, maybe the effects are exaggerated and other groups don't need the supplementation. PS Computational biology is cool, I did programming work in a bio lab trying to identify splicing sites back in undergrad.
berntb 17y ago
Vitamin D seems to be good for general cancer prevention. http://en.wikipedia.org/wiki/Vitamin_D#Role_in_cancer_prevention_and_recovery http://en.wikipedia.org/wiki/Vitamin_D#Role_in_cancer_preven... Otherwise, this is fun! :-) "High Calcium And Vitamin D Intakes Associated WIth Higher Risk Of Cognitive Impairment In Elderly" http://www.sciencedaily.com/releases/2007/05/070501115230.htm http://www.sciencedaily.com/releases/2007/05/070501115230.ht... "Low Levels Of Vitamin D Link To Cognitive Problems In Older People" http://www.sciencedaily.com/releases/2009/01/090122093918.htm http://www.sciencedaily.com/releases/2009/01/090122093918.ht... But I guess most kids here below 35 don't think about using the keyboard after 50. Yet. :-)

timr 17y ago

"It's not vitamin D. It may be vitamin D or it may be vitamin D + calcium. Why didn't they have a group that was supplementing only vitamin D and not calcium? I don't know, but since they didn't test that, there's no way to know that it is just vitamin D." The first rule of scientific criticism is: always read the paper. The classic clinical manifestation of a Vitamin D deficiency is rickets -- the direct consequence of a calcium deficiency. This is because vitamin D is a known enhancer of calcium absorption from the intestine. All other benefits are hypothetical. In light of this information, the researchers controlled for the variability of dietary calcium across participants in the study; they chose to supplement calcium for everyone up to the highest US RDA value. Does that mean that it might be the combination of calcium + vitamin D that conveys the greatest benefit? Well, yes, in fact, that turns out to be true. But since it's trivially easy to supplement calcium and vitamin D simultaneously (and nearly every vitamin D supplement that you can buy includes a calcium supplement), clinically speaking, it makes no difference. But most importantly, the title of the original paper is "Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial." (http://www.ncbi.nlm.nih.gov/pubmed/17556697?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum http://www.ncbi.nlm.nih.gov/pubmed/17556697?ordinalpos=1&#38...), suggesting that the authors are well aware of the relationship between the substances, and are actually interested in the combined effect of calcium and vitamin D. They wanted to know if calcium + vitamin D had a greater cancer-reducing effect than calcium alone, and found that it did. As for your other critiques, the authors state right there in the abstract of the paper that the results are for postmenopausal women in Nebraska, and they don't try to overgeneralize. But since the relationship between vitamin D and calcium are the same for men and women, it's really not unreasonable to suggest that the results could apply more generally -- even if you had to adjust the nutrient levels to fit the age, sex and location of the patient.

jimmybot 17y ago
Wha...? Wait a second. The title for the link submitted is: Vitamin D slashes risk of cancers by 77 percent (2007) If what you're saying is true, that calcium + vitamin D confers the greatest benefit, then the link title is still wrong. But what in the study says that calcium + vitamin D conveys the greatest benefit? (ie Vitamin D alone wouldn't convey as great a benefit) It may be true, but it's not obvious from the article that was linked, and it's still not obvious from the original paper that you linked to. The article and you are assuming that what is having the anti-cancer effect is the calcium, and the vitamin D helps you absorb the calcium, thus enhancing that effect. First, I don't assume what you do, which is that supplementing calcium is always a positive. Second, what if vitamin D has some action other than help you absorb calcium. Even if I'm not an expert in this, I find it hard to believe that medical researchers have completely precluded vitamin D from having any action other than help your body absorb calcium, and if it alone helped prevent cancer, it may be really nice to know, especially if you don't want to be increasing your calcium. I don't get the attitude. I was talking about the information was provided by the article. There may very well be a study about men 20-40 years old, of varying ethnic backgrounds, who take just vitamin D (no calcium) and it's found to decrease cancer versus control, but that's not the information provided here by the article or the original study. Your point about actual vitamin D supplements on the market mostly coming with calcium suffers from the same logical problem. The article headline (original or on HN) should tell me what exactly is decreasing the cancer risk, not some assumption about what consumers will end up buying and what they'll likely also end up supplementing with additionally. If the conclusion had been vitamin D alone decreases the risk of cancer, do you think there wouldn't be manufacturers churning out pure vitamin D, without the calcium? EDIT: Okay, parent has updated post. I appreciate that you softened your tone. Sure, I know it says that they aren't sure of the generality of the study in the article. I think it's worth pointing out because again, there's that disconnect between the title and the content. Title says "TAKE VITAMIN D" without qualification. Article says different. Responding to your new point about the generality of the study--if the requirements for men and women really are the same (I don't buy it), then why study post-menopausal white women in Nebraska? I can see age for the cancer risk, but why not men, and why not of different ethnicities? If you're going to tell me that post-menopausal white women 55 and older are more likely to be deficient in calcium and vitamin D, then well, maybe the effects are exaggerated and other groups don't need the supplementation. PS Computational biology is cool, I did programming work in a bio lab trying to identify splicing sites back in undergrad.

berntb 17y ago

Vitamin D seems to be good for general cancer prevention. http://en.wikipedia.org/wiki/Vitamin_D#Role_in_cancer_prevention_and_recovery http://en.wikipedia.org/wiki/Vitamin_D#Role_in_cancer_preven... Otherwise, this is fun! :-) "High Calcium And Vitamin D Intakes Associated WIth Higher Risk Of Cognitive Impairment In Elderly" http://www.sciencedaily.com/releases/2007/05/070501115230.htm http://www.sciencedaily.com/releases/2007/05/070501115230.ht... "Low Levels Of Vitamin D Link To Cognitive Problems In Older People" http://www.sciencedaily.com/releases/2009/01/090122093918.htm http://www.sciencedaily.com/releases/2009/01/090122093918.ht... But I guess most kids here below 35 don't think about using the keyboard after 50. Yet. :-)