Oral Contraceptives (which increase Vitamin D) reduce the risk of some cancers – Jan 2018

Oral Contraceptives Reduce Risk for Ovarian and Endometrial Cancers New York Times Jan 2018

• “ . . the effect is especially evident in smokers, the obese and those who exercise infrequently. .
  These people are at high risk of being Vitamin D deficient
• “… those who had used them for 10 years or more had a 34 percent reduced risk for endometrial cancer…”
• “Contraceptive use did not seem to affect the risk for postmenopausal colorectal or breast cancer.”

Results (from the JAMA abstract)   doi:10.1001/jamaoncol.2017.4942
The analytic population was aged 50 to 71 years (median, 62 years) at enrollment and largely white (91%) and postmenopausal (96%). For

• ovarian cancer, OC use–associated risk reductions strengthened with duration of use (long-term OC use [≥10 years] HR, 0.60; 95% CI, 0.47-0.76; P < .001 for trend) and were similar across modifiable lifestyle factors.
• Risk reductions for endometrial cancer strengthened with duration of use (long-term OC use HR, 0.66; 95% CI, 0.56-0.78; P < .001 for trend);
• the most pronounced reductions were among long-term OC users who were
  • smokers (HR, 0.47; 95% CI, 0.25-0.88), had
  • obese BMIs (0.36; 95% CI, 0.25-0.52), and who
  • exercised rarely (HR, 0.40; 95% CI, 0.29-0.56).
• Associations between OC use and breast and colorectal cancers were predominantly null.

Note by VitaminDWikik – breast and colorectal cancers usually do not start until years after contraceptives are stopped

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See also VitaminDWiki

• Ovarian cancer risk increases 27 percent for each 8 ng lower level of Vitamin D – Sept 2016
• Oral contraceptive use associated with higher levels of vitamin D – thesis June 2012
• Estrogen contraception pill doubled the response to 1,000 IU of vitamin D – RCT Sept 2017
• All items in category Iron and Vitamin D 68 items
  Wonder if the boost in Vitamin D levels is associated with the boost in Iron