OBJECTIVES To examine the effect of 25‐hydroxyvitamin D (25(OH)D) levels recommended by Endocrine Society guidelines (>30 ng/mL) on cognition in healthy older African‐American women over 3 years. DESIGN Randomized, double‐blind, placebo‐controlled clinical trial. SETTING Bone Mineral Research Center at New York University Winthrop Hospital. PARTICIPANTS Healthy postmenopausal African American women aged 65 and older (N=260; mean age 68.2 ± 4.9; 46% college education or higher). INTERVENTION Half of the women were randomized to receive vitamin D (adjusted to achieve a serum level > 30 ng/mL) with calcium (diet and supplement total of 1,200 mg), and half were randomized to receive placebo with calcium (1,200 mg). MEASUREMENTS Cognitive assessments every 6 months using the Mini‐Mental State Examination (MMSE) to detect cognitive decline. Mean MMSE scores were calculated over time for both groups. Those with MMSE scores less than 21 at baseline were excluded. RESULTS The average dose of vitamin D3 was 3,490 ± 1,465 IU per day, and average serum 25(OH)D at 3 years was 46.8 ± 1.2 ng/mL in the active group and 20.7 ± 1.1 ng/mL in the placebo group. Serum 25(OH)D concentration was maintained at greater than 30 ng/mL in 90% of the active group. Over the 3‐year period, MMSE scores increased in both groups (p < .001), although change over time was not significantly different between the groups. No adverse events associated with vitamin D were observed. CONCLUSION There was no difference in cognition over time between older African‐American women with serum concentrations of 25(OH)D of 30 ng/mL and greater than those taking placebo. There is no evidence to support vitamin D intake greater than the recommended daily allowance in this population for preventing cognitive decline. J Am Geriatr Soc 67:81–86, 2019.
The arterial vasa vasorum is a specialized microvasculature that provides critical perfusion required for the health of the arterial wall, and is increasingly recognized to play a central role in atherogenesis. Cardio-metabolic disease (CMD) (including hypertension, metabolic syndrome, obesity, diabetes, and pre-diabetes) is associated with insulin resistance, and characteristically injures the microvasculature in multiple tissues, (e.g., the eye, kidney, muscle, and heart). CMD also increases the risk for atherosclerotic vascular disease. Despite this, the impact of CMD on vasa vasorum structure and function has been little studied. Here we review emerging information on the early impact of CMD on the microvasculature in multiple tissues and consider the potential impact on atherosclerosis development and progression, if vasa vasorum is similarly affected.
Purpose : Bone Mineral density (BMD) is a predictor of fracture risk. Beyond BMD, the role of vitamin D for bone strength is not known in African American (AA) population. Objective: To examine the effect of vitamin D supplementation on femoral neck (FN) strength. Design and Setting : A 3-year randomized, double-blind, placebo-controlled clinical trial. Participants : 260 healthy postmenopausal AA women aged 65 years and older. Main Outcome Measures : Femoral axis length and width were measured by dual-energy x-ray absorptiometry. We combined these variables with BMD, body weight and height and computed composite indices of FN strength: compression strength index (CSI), bending strength index (BSI), and impact strength index (ISI). Results: Mean age of participants was 68.2 ± 4.9 years. Baseline characteristics between groups were similar. The average dose of vitamin D3 was 3490 ± 1465 IU/day. Serum 25(OH)D concentration was maintained at above 30 ng/mL in the active group. The average serum 25(OH)D at the 3-year period was 46.8 ± 1.2 ng/mL in the active group compared to 20.7 ± 1.1 ng/mL in the placebo group. Linear mixed effects models demonstrated a significant linear increase in FN width, BSI and ISI over time in both active and placebo group (all p values <0.05). However, there was no group × time interaction effect for any composite indices suggesting that the longitudinal differences in CSI, BSI and ISI between groups were not statistically significant (all p values >0.05). Conclusion : These findings indicate no treatment effect of vitamin D on bone strength in African Americans. Maintaining serum 25(OH)D above 30 ng/ml did not affect bone strength. There is no evidence to support vitamin D intake greater than the recommended RDA by the Institute of Medicine in this population for bone health.
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