Many of you have heard of the Women’s Health Initiative (WHI) study currently going on. Its a long term study of tens of thousands of women, focusing on their lifestyle and what may influence any health problems they develop. One of the benefits of these big studies is that scientists can pull out pockets of data and analyze them, giving us a lot of different information without conducting whole new studies.
One very interesting connection was found when looking to see if calcium + vitamin D supplements reduced rates of hip fracture and/or skin cancer: calcium and vitamin D supplements were associated with a 55% reduced rate of melanoma in women who had previously had non-melanoma skin cancer (NMSC). Most of these non-melanoma cancers are basal-cell cancers, those buggers the dermatologist slices off seemingly every time you go in to see her. (Or maybe that’s just me.)
The headline on this analysis you are most likely to hear is “Calcium and Vitamin D do NOT reduce the rate of melanoma!” Here’s why: for people with no history of NMSC, there was no reduction in melanoma rates between those taking the supplements and those who did not take them. But since this study was so large, the researchers could break it down further, and look at those who are most at risk for melanoma: those who have had prior skin cancers.
This is why I write and post here: the headline rarely tells the whole story. And I want you all to be in the know.
Now, calcium supplementation has come under fire recently and deservedly so. We were all told to take lots of calcium for our bones before much research came back on the effectiveness of this supplementation. It made sense, calcium is the main building block of bone, so we need to get more of it. But building bone is more complex than that, and there are some problems with taking large amounts of calcium in supplement form. The recommended amounts of vitamin D have also just been revised, with 600 IU a day the new norm (800IU for people over 71).
The study dose was 1,000 mg of calcium and 400 IU (international units) of Vitamin D, the standard recommendation when this study was started over 7 years ago. It was tested against a placebo in a double-blind design. A new study is starting with revised supplement dosages – but we will not have the data on that for several years. In another analysis of this study, those women with the lowest levels of vitamin D in their blood at the start of the study had higher risk of developing melanoma.
So here’s the bottom line: if you have had skin cancer, or are at high risk of skin cancer, taking a calcium + vitamin D3 supplement would be prudent (unless of course your physician advises against it for other health reasons). If you get a fair amount of calcium from food, meaning if you eat some form of dairy on most days and get your leafy greens on most days, then a supplement with 600mg of calcium (the new norm for most pills) and 400 – 600 IU of vitamin D3 is a good place to start. It is my opinion that we will see the same results with this level of dosing, and maybe even more impact with more vitamin D.
If you do not eat any dairy and leafy greens are not your thing (say it aint so!), then 1,000 mg of calcium plus the 400 – 600IU of vitamin D is fine. The RDA is 1,000 mg per day for women under 50 and men, and 1,200 mg a day for women over 50. Most of the concern is with supplement dosages over 1,200 mg of calcium per day, so keep your level under that unless you are specifically instructed to take more by your physician. If your vitamin D levels are low, then take the amount recommended by your doctor and factor in any vitamin D in your calcium supplement to your total for the day. If you take these nutrients in separate pills, then take the pills at the same time to get the most benefit. Long story, you’ll have to trust me on this one.
It is ironic, isn’t it, that we go into the sun to get more vitamin D, but then get skin cancer from too much sun, which is then prevented by having enough vitamin D. One big ball of confusion. Or one big ball of global warming/ozone layer/pollution. Anyway, the best we know right now is to use sunscreen, take a few vitamins, and (even though it is the most humbling experience ever) see our derms for a skin check every year.
Knowledge is power.