Optimizing Vitamin D Status to Reduce Colorectal Cancer Risk: An Evidentiary Review

Osteoporosis self-assessment tool for Asians as a simple risk index of identifying a poor prognosis in women surgically treated for colorectal cancer

BACKGROUND

Osteoporosis and colorectal cancer (CRC) in older women are considered enormous public health burdens. The effects of osteoporosis on the oncologic outcome of CRC surgery are poorly understood. We evaluated the use of the Osteoporosis Self-assessment Tool for Asians (OSTA) for predicting postoperative outcome in older women after receiving surgical treatment of CRC.

MATERIALS AND METHODS

The present single-institution retrospective study analyzed patients who had undergone surgery for CRC in 2002-2008. To characterize the major population of women with osteoporosis, which consists of postmenopausal women, only patients aged 50 years and older were analyzed. Their OSTA scores were evaluated for correlations with cancer-specific survival after surgery for CRC by performing univariate, multivariate, and survival analyses.

RESULTS

During a 7-year period, 440 women were studied. The cancer-specific mortality and overall mortality rate was 28.4% and 33.4%, respectively. The univariate analyses revealed that significant predictors of cancer-specific mortality after CRC surgery were the International Union Against Cancer (UICC) stage, OSTA category, histologic grading, lymph node metastases, and tumor invasion depth. After risk adjustment, the UICC stage and OSTA risk index were independent predictors of mortality. A comparison of OSTA risk index among patients with different UICC stages showed that the accuracy of the index in predicting cancer-specific survival after CRC surgery was greatest for patients with stage II and III disease.

CONCLUSIONS

The UICC stage and OSTA risk status showed independent positive associations with postoperative mortality in aged female patients with CRC. Moreover, the OSTA index had a particularly strong association with cancer-specific mortality in patients with UICC stage II and III.

Variation in vitamin D supplementation among adults in a multi-race/ethnic health plan population, 2008

Background

Vitamin D may have a role in many chronic conditions in addition to bone health. Nutritional surveys among Americans have reported high levels of vitamin D insufficiency, especially among Blacks and Latinos. Our study examined variation in vitamin D supplementation practices in an adult health plan population by age, gender, and race-ethnicity.

Methods

Self-report data from a 2008 general health survey in a large Northern California health plan were used to characterize number and types of sources of vitamin D supplementation (multivitamin, calcium with D, singular D) among women and men aged 25-85, overall, by race-ethnicity, and for obese, diabetic, and hypertensive subgroups.

Results

In this population, 40% of women and 54% of men ≤ 50, and 24% of women and 53% of men aged 51-85 get no vitamin D from dietary supplements. Higher vitamin D supplementation among women > 50 is associated with higher reported intake of calcium with D. Black and Latina women aged 25-85 and Filipinas in the ≤ 50 age group were significantly less likely than non-Hispanic Whites to get vitamin D from supplements, whereas vitamin D supplementation practices among Chinese women did not significantly differ from non-Hispanic Whites. Among men, Latinos aged 25-85 and Black and Chinese ≤ 50 were significantly less likely than non-Hispanic Whites to get vitamin D from supplements. Similar race-ethnic differences in vitamin D supplementation patterns were observed for people in the obese, diabetic, and hypertensive groups.

Conclusions

Our survey results suggest that in 2008, a large percentage of women and an even larger percentage of men in a large Northern California health plan get no vitamin D from dietary supplements, and that Blacks and Latinos and obese adults, who are at higher risk of vitamin D deficiency, are also the least likely to get any vitamin D from dietary supplements.

Nutritional strategies for successful aging

With increasing life expectancy in developed and developing countries, maintaining health and function in old age has become an important goal, including avoidance or optimal control of chronic diseases; maintenance or retarding the decline of physical and cognitive function; optimizing psychological health; and maintaining independent functioning in tasks related to self-care and societal interaction. This article discusses all of those, as well as other components of successful aging such as social network and socioeconomic status.

Impact of oral vitamin D supplementation on serum 25-hydroxyvitamin D levels in oncology

BACKGROUND

Serum 25-hydroxyvitamin D [25(OH)D] is the major circulating form of vitamin D and a standard indicator of vitamin D status. Emerging evidence in the literature suggests a high prevalence of suboptimal vitamin D (as defined by serum 25(OH)D levels of <32 ng/ml) as well as an association between lower serum levels and higher mortality in cancer. We investigated the effect of oral vitamin D supplementation as a means for restoring suboptimal levels to optimal levels in cancer.

METHODS

This is a retrospective observational study of 2198 cancer patients who had a baseline test prior to initiation of cancer therapy at our hospital to evaluate serum 25(OH)D levels between Jan 08 and Dec 09 as part of their initial nutritional evaluation. Patients with baseline levels of < = 32 ng/ml (n = 1651) were considered to have suboptimal serum 25(OH)D levels and were supplemented with 8000 IU of Vitamin D3 (four 2000 IU D3 capsules) daily as part of their nutritional care plan. The patients were retested at their first follow-up visit. Of 1651 patients, 799 were available for follow up assessment. The mean serum 25(OH)D levels were compared in these 799 patients across the 2 time points (baseline and first follow-up) using paired sample t-test. We also investigated the factors associated with response to vitamin D supplementation.

RESULTS

Of 2198 patients, 814 were males and 1384 females. 1051 were newly diagnosed and treated at our hospital while 1147 were diagnosed and treated elsewhere. The mean age at presentation was 55.4 years. The most common cancer types were breast (500, 22.7%), lung (328, 14.9%), pancreas (214, 9.7%), colorectal (204, 9.3%) and prostate (185, 8.4%). The mean time duration between baseline and first follow-up assessment was 14.7 weeks (median 10.9 weeks and range 4 weeks to 97.1 weeks). The mean serum 25(OH)D levels were 19.1 ng/ml (SD = 7.5) and 36.2 ng/ml (SD = 17.1) at baseline and first follow-up respectively; p < 0.001. Patients with prostate and lung cancer had the highest percentage of responders (70% and 69.2% respectively) while those with colorectal and pancreas had the lowest (46.7% each). Similarly, patients with serum levels 20-32 ng/ml at baseline were most likely to attain levels > 32 ng/ml compared to patients with baseline levels < 20 ng/ml.

CONCLUSIONS

The response to supplementation from suboptimal to optimal levels was greatest in patients with prostate and lung cancer as well as those with baseline levels between 20-32 ng/ml. Characteristics of non-responders as well as those who take longer to respond to supplementation need to be further studied and defined. Additionally, the impact of improved serum 25(OH)D levels on patient survival and quality of life needs to be investigated.

Relation between prediagnostic serum 25-hydroxyvitamin D level and incidence of breast, colorectal, and other cancers

The evidence is increasing that higher serum 25-hydroxyvitamin D [25(OH)D] levels reduce the risk of many types of cancer. Ecological and observational studies yield the strongest evidence, with support from studies of mechanisms. A key question is identifying the relation between serum 25(OH)D level and cancer incidence. Meta-analyses of such studies is a reasonable approach to determine the serum 25(OH)D level-cancer incidence relation. This paper reports new meta-analyses for breast and colorectal cancers. Currently, the journal literature offers seven prospective breast cancer and ten prospective colorectal cancer studies that can be used. The data for these studies graphed and compared. Data from some of the studies were multiplied by factors to bring all the studies into reasonable agreement with a tentative dose-response relation. The data were fit with a variety of functions; the best fits were nonlinear functions that tended to asymptotically reach a lower odds ratio at higher serum 25(OH)D levels. These analyses estimated that the 50% reduction in incidence occurs for a value of 78 nmol/L compared with the value at 24 nmol/L for breast cancer, and a value of 60 nmol/L compared with the value at 15 nmol/L for colorectal cancer. Although these results are reasonable, some concern exists that a single serum 25(OH)D level, measured years prior to diagnosis of cancer, does not adequately represent the serum levels for the entire period before diagnosis. Future prospective studies should include more serum 25(OH)D level measurements during the study course.