HOUSTON — Vitamin D deficiency doesn’t just increase the risk of osteoporosis and other bone disorders, it dramatically increases the risk of death in older cancer patients with solid tumors, according to researchers at the Central Texas Veterans Healthcare System in Temple, and the University of Texas MD Anderson Cancer Center in Houston.

In a study released in conjunction with the 2018 American Society of Clinical Oncology Annual Meeting being held this weekend in Chicago, the VA researchers found that vitamin D deficiency increased the risk of death 80% in older patients with solid tumors, but not in those with hematologic malignancies.

Of 457 cancer patients referred to MD Anderson Cancer Center for geriatric assessment, 302 had bone density analysis and 396 had vitamin D levels assessed, as recommended by the National Osteoporosis Foundation Guidelines. The researchers found bone health disorders in 77% of the patients tested, while 70% of geriatric cancer patients had vitamin D insufficiency (49%) or deficiency (21%).

Analysis indicated that Vitamin D deficiency was a risk factor for overall survival (OS) in solid tumors, with a hazard ratio of 1.80 (95% CI = 1.08, 2.99, p = 0.02). During a maximum follow-up period of three years, 153 patients (33%) died.
The study contributes important findings to an ongoing debate about appropriate calcium levels, generally, and their impact on cancer risk. The Texas researchers defined insufficiency as 25-hydroxy-vitamin D [25(OH)D] less than 30 ng/ml and deficiency as levels less than 20 ng/ml.

In 2010, the National Academy of Medicine of the National Academies of Sciences, Engineering, and Medicine, formerly the Institute of Medicine, recommended maintaining blood concentrations of calcium above 20 ng/ml and many studies subsequently considered lower levels deficient. The Endocrine Society recommended in 2011 that individuals maintain a minimum level of 30 ng/ml and advised that, to stay on the safe side, children and adults should keep vitamin D levels between 40 ng/ml and 60 ng/ml.2

In 2016, several of the authors of the original National Academy recommendation clarified their recommendation in an article in the New England Journal of Medicine, saying that the 20 ng/ml level has been misunderstood as a minimum, when it represented a value in the upper end of the preferred range. It was designed to include a generous margin to account for variations in nutritional needs and assumed zero or minimal sun exposure.3 They recommended considering a serum 25(OH)D level below 12.5 ng/ml as deficient in generally healthy individuals.

Multiple studies and meta-analyses have reached conflicting results in terms of the association between cancer and vitamin D levels. Higher levels of vitamin D appear to be protective in colorectal and bladder cancer. While higher vitamin D concentrations increase the risk of prostate cancer, they are also associated with higher survival rates in individuals who develop prostate cancer.4

“Vitamin D deficiency is common in older cancer patients and is associated with overall survival in older cancer patients with solid tumors. Prospective studies are needed,” authors of the recent study concluded.

1Jara-Almonte Edwards B, Zhang X, Pang L, Sun M, Geng Y, Hedberg A-M, Tripathy D, Champlin R, Popat UR, Dinney CPN. Vitamin D deficiency in older cancer patients with solid tumors, effect on overall survival. 2018 ASCO Annual Meeting. Abstract e22038.

2Tello M. Vitamin D: What’s the “right” level? Harvard Health Blog. December 19, 2016.

3Manson JE, Brannon PM, Rosen CJ, Taylor CL. Vitamin D Deficiency — Is There Really a Pandemic? N Engl J Med. 2016 Nov 10;375(19):1817-1820.

4Mondul AM, Weinstein SJ, Layne TM, Albanes D. Vitamin D and Cancer Risk and Mortality: State of the Science, Gaps, and Challenges. Epidemiologic Reviews. 2017;39(1):28-48.