Possible Role of Serum 25-Hydroxyvitamin D in Black–White Health Disparities in the United States
William B. Grant, PhDa wbgrant at infionline.net, Alan N. Peiris, MD, PhD, MRCP (UK)b
Volume 11, Issue 9, Pages 617-628 (November 2010)
Journal of the American Medical Directors Association published online 01 October 2010.
Significant health disparities exist between African Americans (AAs) and White Americans (WAs). The all-cause mortality rate for AAs in 2006 was 26% higher than for non-Hispanic WAs. Explanations for the disparities usually include socioeconomic status, lifestyle behaviors, social environment, and access to preventive health care services. However, several studies indicate that these factors do not account for the observed disparities. Many studies report that vitamin D has important health benefits through paracrine and autocrine mechanisms and that higher serum 25-hydroxyvitamin D (25OHD) levels are associated with better health outcomes. AAs have a population mean serum 25(OH)D level of 16 ng/mL, whereas WAs have a level of 26 ng/mL. From preliminary meta-analyses of serum 25(OH)D level–disease outcome from observational studies, differences in serum 25(OH)D level for AAs and WAs can explain many of the health disparities.
The ratios of mortality rates for AAs to WAs for female breast cancer, colorectal cancer, cardiovascular disease, and all-cause mortality rate in 2006 were 1.34, 1.43, 1.29, and 1.26, respectively.
The 25(OH)D level–disease outcome ratios for 16 ng/mL versus 26 ng/mL for the same diseases were 1.26, 1.44, 1.27, and 1.26, respectively. The close agreement between these 2 sets of numbers suggests that low serum 25(OH)D level is an important health risk for AAs. Given the widespread vitamin D deficiency in the AA population and the potential widespread health benefits that accompany adequate replacement, we believe that addressing this issue may be the single most important public health measure that can be undertaken.
| Black Disparity | 16 vs 26 ng/ml | ||
| breast cancer | 1.34 | 1.26 | |
| colorectal cancer | 1.43 | 1.44 | |
| cardiovascular disease | 1.29 | 1.27 | |
| all-cause mortality | 1.26 | 1.26 | |
Table 3 (extracted from PDF). Reports Related to Vitamin D and Disease Outcome for AAs versus WAs
references in PDF not included
| Disease | Finding | ||
| Cardiovascular disease (CVD | ) Burden of CVDs increased with lower 25(OH)D categories, with 5.3%, 6.7%, and 7.3% coronary heart disease; 1.5%, 2.4%, and 3.2% heart failure; 2.5%, 2.0%, and 3.2% stroke; and 3.6%, 5.0%, and 7.7% peripheral arterial disease. Across all CVDs, hypovitaminosis D was more common in blacks than Hispanics or whites. | ||
| Peripheral arterial disease (PAD) | AAs had higher odds of PAD in age- and sex-matched models (OR 5 3.1; 95% CI, 1.5–6.4; P \.01), an association that was modestly attenuated by adjustment for traditional (OR 5 2.4; 95% CI, 0.9–6.1; P 5 .06) CVD risk factors. Mean ( SEM) 25(OH)D concentrations were significantly lower in black than in white adults (39.2 1.0 and 63.7 1.1 nmol/L, respectively; P \.001). After adjustment for racial differences in socioeconomic status and for traditional and novel risk factors, ORs for PAD in black compared with white adults were 1.67 (95% CI, 1.11–2.51). | ||
| Congestive heart failure (CHF | Risk of developing CHF was higher among AA than white participants (hazard ratio, 1.8; 95% CI, 1.1–3.1), adding hypertension and/or diabetes mellitus to models including ethnicity eliminated statistical ethnic differences in incident CHF. | ||
| Glucose metabolism | 51 AA adolescent females (body mass index, 43.3 9.9 kg/m2; age, 14 2 y) were studied. Serum 25(OH)D concentrations were 20 ng/mL or less in 78.4% and 15 ng/mL or less in 60.8% of subjects. The Matsuda index of insulin sensitivity was significantly lower (P 5.02), and insulin area under the curve was significantly higher (P 5 .04) in subjects with 25(OH)D concentrations of 15 ng/mL or less versus those with higher concentrations. | ||
| Cognitive impairment | AAs had a lower mean 25(OH)D level (17.98 ng/mL; SD, 6.9) compared with WAs (25.20 ng/mL; SD, 7.0; P \.0001). Participants with vitamin D deficiency performed worse on a measure of cognitive performance, the Short Blessed Test (10.87 versus 6.31) and t scores (–1.29 versus –0.72) of the hip. | ||
| Chronic kidney disease | Overall, blacks had similar 1,25D levels compared with non-blacks, but significantly lower levels of 25D with higher levels of calcium, phosphorus, and parathyroid hormone, and were significantly more likely to have hyperphosphatemia than non-blacks. | ||
| End-stage renal disease (ESRD | After adjustment for clinical covariates but not 25(OH)D levels, non-Hispanic black individuals had a 2.83-fold (95% CI, 1.03–7.77) higher risk for developing ESRD than non-Hispanic white individuals. Additional adjustment for 25(OH)D levels reduced the risk by 58% (incidence rateratio, 1.77; 95% CI, 0.38–8.21). | ||
| Diabetes | Adjusting for sex, age, BMI, leisure activity, and quarter of year, ethnicity- specific ORs for diabetes (fasting glucose $ 7.0 mmol/L) varied inversely across quartiles of 25OHD in a dose-dependent pattern (OR 0.25 95% CI 0.11–0.60 for non-Hispanic whites) in the highest vitamin D quartile (25OHD $ 81.0 nmol/L) compared with the lowest 25OHD ($ 43.9 nmol/L). This inverse association was not observed in non-Hispanic blacks. | ||
| Cancer | Ecological studies found solar UVB significantly inversely correlated with mortality rates for breast, colon, esophageal, gastric, and rectal cancers for AAs, albeit with lower associations than for WAs. Smoking and alcohol consumption were also significantly correlated with several cancers. | ||
| Breast cancer | Invasive breast cancer age-adjusted incidence for black women age \40 y was significantly higher than those for white women (rate ratio 5 1.16; 95% CI, 1.10–1.23). Age-adjusted mortality rate for black women age \40 y was twice that for white women. Multivariate regression models controlled for age, body mass index (in kg/m2), race-ethnicity, geography, season, physical activity, diet, and cancer treatments showed that stage of disease independently predicted serum 25(OH)D (P 5 .02). | ||
| Colorectal cancer (CRC) | Several studies, however, have shown that an increased risk of CRC death among AAs remains even after controlling for tumor stage at diagnosis, socioeconomic factors, and comorbidity. | ||
| Cancers | Association between race and cancer mortality rates, adjusted HR:premenopausal breast cancer, 1.43 (95% CI, 1.11–1.84); postmenopausal breast cancer, 1.48 (95% CI, 1.27–1.72); advanced NHL, 1.17 (95% CI, 0.94–1.45); advanced ovarian cancer, 1.65 (95% CI, 1.21–2.24); advanced- stage prostate cancer, 1.19 (95% CI, 1.05–1.35) | ||
| Influenza, common cold | In a randomized controlled trial involving AA postmenopausal women, a 40% reduction in colds or influenza with 800 IU/d and 92% reduction with 2000 IU/day was found. | ||
| Sepsis | Black persons (proportionate ratio, 1.25, 95% CI, 1.18–1.32) remained more likely to have gram-positive infections. Blacks had greater hospitalization rates than whites, with the greatest disparity between the ages of 35 and 44 y (relative risk, 4.35; 95% CI, 3.93–4.82). Compared with whites, blacks had higher age-adjusted rates for hospitalization and mortality but similar case fatality rates. | ||
| All-cause mortality rate | Deficiency in vitamin D was linked to higher rates of death among all participants. Those most deficient in vitamin D had a 40% higher risk of death from cardiac illness. Adjusting for race showed that blacks had a 38% higher risk of death than whites. However, this risk of death went down as vitamin D levels went up. Adjusting for poverty had a similar effect. | ||
AA, African American;
CI, confidence interval;
HR, hazard ratio;
NHL, non-Hodgkin’s lymphoma;
OR, odds ratio;
RR, relative risk;
WA, white American.
See also Vitamin D Life
- Hypothesis: Blacks get more cancer than whites due to lower levels of vitamin D – June 2012 same authors
- Racial differences in health problems (premature births) disappeared when vitamin D levels were the same – April 2018
- Blacks die more often than whites of many diseases (they have less vitamin D) – 2012 contains the following summary
Cancer Facts & Figures for African Americans Cancer.org
- “African Americans have the highest death rate and shortest survival of any racial and ethnic group in the US for most cancers”
- Has a huge number of tables and charts, Note: Vitamin D is not mentioned
Leading Causes of Death as of March 2018
| All Ages Death rate | Black | White | Ratio |
| Heart diseases | 217 | 171 | 1.27 |
| Cancer | 199 | 170 | 1.17 |
| Cerebrovascular diseases | 51 | 36 | 1.4 |
| Diabetes | 40 | 19 | 2.0 |
Rates per 100,000 Age adjusted Non-Hispanic
Items in both categories Diabetes and Dark Skin
- Children in India – 1 in 7 extremely low Vitamin D, 1 in 10 prediabetic – Sept 2019
- Blacks die more often than whites of many diseases (they have less vitamin D) – 2012
- Diabetic blacks – 80 percent had low vitamin D (less than 20 ng) a decade before – Sept 2017
- Diabetes is associated with low vitamin D in various races, but not blacks – Sept 2015
- Diabetes (Type 1) 14X more likely in dark skin children with low levels of vitamin D – May 2015
- Obese diabetics with dark skins not benefit from 6,000 IU of vitamin D daily (no surprise) – RCT March 2015
- Diabetic glycation control is inversely related to Vitamin D in India – Feb 2015
- Type I diabetes in dark skin children associated with low vitamin D if far from equator – Jan 2015
- Dr. Holick video on vitamin D - March 2013
- African-Americans at high risk of obesity and diabetes - 2011
- Type 1 Diabetes associated with low vitamin D, especially in dark skinned youths – Dec 2012
- Hyperglycemia in black veterans is associated with low vitamin D – Nov 2012
- Diabetics with darker skin were more vitamin D deficient – May 2012
- Low vitamin D associated with obesity-related diseases for ethnic minorities – Sept 2011
- 97 percent of Native American children have less than 30 ng of vitamin D – Oct 2011
- Diabetic neuropathy and low vitamin D, especially in blacks - July 2011
- Studies linked low vitamin D and dark skin to Obesity, Diabetes, and heart – June 2011
- Not yet certain that vitamin D reduces cardiovascular and diabetes in blacks – Mar 2011
- Diabetes Statistics including more diabetes with darker skin – 2007
- Insulin resistance correlated with low vitamin D levels in Arab Americans – June 2010
- Insulin sensitivity associated with Vit D in A-A April 2010
- Vitamin D deficiency and insulin insensitivity in African Americans - 2010
Black Americans get diabetic foot amputations 3X more often than whites ProPublica May 2020
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