New evidence that many Americans don't get sufficient vitamin D!

These quotes are from an NIH-funded study at Mayo Clinic, just published by the the American Society of Hematology in its medical journal "Blood" (Shanafelt TD, et al. Vitamin D insufficiency and prognosis in chronic lymphocytic leukemia (CLL). Blood. 2010 Nov 3. PMID: 21048153). It suggests that 30-40% of the general population is deficient in vitamin D, and that this vitamin has a "central role" in the body beyond bone health:

"Vitamin D insufficiency is common globally and in the United States. Approximately 25-50% of patients seen in routine clinical practice have vitamin D levels below the optimal range, and it is estimated that up to 1 billion people worldwide have vitamin D insufficiency." 1-3

"Vitamin D has a central role in maintaining serum calcium and skeletal homeostasis as well as multiple other cellular effects including regulation of differentiation, proliferation, apoptosis, metastatic potential, and angiogenesis.5 Several reports now suggest low serum 25(OH)D levels may be associated with increased incidence of colorectal,6,7 breast,8,9 and other cancers.10 Consistent with these results, one population based, double-blind, randomized placebo-controlled trial found women who increased their daily vitamin D intake by 1100 IU reduced their risk of cancer by 60-77%." 11

"Consistent with the prevalence of hypovitaminosis D in the general population,1-3 30-40% of CLL patients in the two observational cohorts studied had vitamin D insufficiency."

These quotes cited the following references in the statements posted above:

1.Thomas MK, Lloyd-Jones DM, Thadhani RI, et al. Hypovitaminosis D in medical inpatients. N Engl J Med. 1998;338(12):777-783.
2. Holick MF. High prevalence of vitamin D inadequacy and implications for health. Mayo Clin Proc. 2006;81(3):353-373.
3. Holick MF. Vitamin D deficiency. N Engl J Med. 2007;357(3):266-281.
5. Bikle D. Nonclassic actions of vitamin D. J Clin Endocrinol Metab. 2009;94(1):26-34.

6. Gorham ED, Garland CF, Garland FC, et al. Vitamin D and prevention of colorectal cancer. J Steroid Biochem Mol Biol. 2005;97(1-2):179-194.
7. Yin L, Grandi N, Raum E, Haug U, Arndt V, Brenner H. Meta-analysis: longitudinal studies of serum vitamin D and colorectal cancer risk. Aliment Pharmacol Ther. 2009;30(2):113-125.
8. Crew KD, Shane E, Cremers S, McMahon DJ, Irani D, Hershman DL. High prevalence of vitamin D deficiency despite supplementation in premenopausal women with breast cancer undergoing adjuvant chemotherapy. J Clin Oncol. 2009;27(13):2151-2156.
9. Chen P, Hu P, Xie D, Qin Y, Wang F, Wang H. Meta-analysis of vitamin D, calcium and the prevention of breast cancer. Breast Cancer Res Treat. 2009.
10. Garland CF, Gorham ED, Mohr SB, Garland FC. Vitamin D for cancer prevention: global
perspective. Ann Epidemiol. 2009;19(7):468-483.
11. Lappe JM, Travers-Gustafson D, Davies KM, Recker RR, Heaney RP. Vitamin D and calcium
supplementation reduces cancer risk: results of a randomized trial. Am J Clin Nutr. 2007;85(6):1586-
1591.