Aromatase Inhibitors are used in post menopausal women to prevent breast cancer recurrence. Aching muscles and joints can be a hazard. High Vitamin D levels help prevent this problem but this is harder to achieve then one would think.
Studies have suggested a link between low vitamin D and pains on letrozol:
J Clin Oncol. 2009 May 1;27(13):2151-6. Epub 2009 Apr 6.
High prevalence of vitamin D deficiency despite supplementation in premenopausal women with breast cancer undergoing adjuvant chemotherapy.
Crew KD, Shane E, Cremers S, McMahon DJ, Irani D, Hershman DL. free article here
- levels less than 20 ng/ml in 66% of white, 80% of black, and 84% of Hispanic women – 20 ng/ml levels are very low with some considering <40ng suboptimal
Breast Cancer Res Treat. 2010 Jan;119(1):111-8. Epub 2009 Aug 5.
Effect of vitamin D supplementation on serum 25-hydroxy vitamin D levels, joint pain, and fatigue in women starting adjuvant letrozole treatment for breast cancer.
Khan QJ, Reddy PS, Kimler BF, Sharma P, Baxa SE, O’Dea AP, Klemp JR, Fabian CJ. abstract here
- “16 weeks of letrozole, more women with 25OHD levels >66 ng/ml (median level) reported no disability from joint pain than did women with levels <66 ng/ml (52 vs. 19%; P = 0.026)." - so 52% of people low are sick versus 19% of those with levels over 66ng/ml. – that’s huge!
- used 50,000 iu/wk for 12 weeks
A recent study shows getting levels up in breast cancer cases is a lot more difficult than one would imagine:
Breast Cancer Res Treat. 2010 Jul 28. [Epub ahead of print]
Vitamin D threshold to prevent aromatase inhibitor-induced arthralgia: a prospective cohort study.
Prieto-Alhambra D, Javaid MK, Servitja S, Arden NK, Martinez-García M, Diez-Perez A, Albanell J, Tusquets I, Nogues X. abstract here
- “90% of women had a 25(OH)D <30 ng/ml at baseline" - ouch, that is terrible
- 800 u Vitamin D3 plus 16,000 units every 2 weeks only got 50% to target (>40 ng/ml) after 6 months
- if low – increase in joint pain (mean 1.16 points SD 2.66; P < 0.001)
- if helped – was significantly (P = 0.02) attenuated in those who reached concentrations of 25(OH)D of >/=40 ng/ml
- Arthalgias (joint aches) helped as well – “a lower risk of incident arthralgia (OR 0.12 ** [0.03 to 0.40]).”
- Conclusion – A target concentration of 40 ng/ml 25OHD may prevent development of AI arthralgia but higher loading doses are required to attain this level in women with deficiency at baseline.”
Comment – current vitamin D recommendations are a joke. In order to obtain any results, you have to use the 50,000 capusles (Osto D2) like in second study and take them once weekly with your usual vitamin D. I frankly think one should continue on that regimen indefinitely as it would probably take over three times that dose to run into any concerns.
I hope oncologists are telling their patients and if not, I hope this information gets out there…