After bariatric surgery, hip bone loss reflects skeletal unloading and cortical bone loss reflects secondary hyperparathyroidism. This study highlights deterioration of cortical bone loss as a novel mechanism for bone loss after bariatric surgery.

Although vitamin D deficiency is prevalent among obese individuals, its cause is poorly understood. Few studies have measured vitamin D concentrations in adipose of obese (OB) subjects, and none have included normal weight controls (C). The goal of this study was to investigate whether the relationship between body composition, serum 25-hydroxyvitamin D (25OHD), vitamin D in subcutaneous (SQ) and omental (OM) adipose, and total adipose stores of vitamin D differ among OB and C. Obese women undergoing bariatric surgery and normal-weight women undergoing abdominal surgery for benign gynecologic conditions were enrolled. Subjects had measurements of serum 25OHD by high-performance liquid chromatography (HPLC) and body composition by dual-energy X-ray absorptiometry (DXA). Vitamin D concentrations in SQ and OM adipose were measured by mass spectroscopy. Thirty-six women were enrolled. Serum 25OHD was similar between groups (OB 27 ± 2 versus C 26 ± 2 ng/mL; p = 0.71). Adipose vitamin D concentrations were not significantly different in either SQ (OB 34 ± 9 versus C 26 ± 12 ng/g; p = 0.63) or OM compartments (OB 51 ± 13 versus C 30 ± 18 ng/g; p = 0.37). The distribution of vitamin D between SQ and OM compartments was similar between groups. Serum 25OHD was directly related to adipose vitamin D in both groups. Total body vitamin D stores were significantly greater in OB than in C (2.3 ± 0.6 versus 0.4 ± 0.8 mg, respectively; p < 0.01).In summary, although OB had significantly greater total vitamin D stores than C, the relationship between serum 25OHD and fat vitamin D and the overall pattern of distribution of vitamin D between the OM and SQ fat compartments was similar. Our data demonstrate that obese subjects have greater adipose stores of vitamin D. They support the hypotheses that the enlarged adipose

Purpose Assess the association of vitamin D deficiency and indices of mineral metabolism with subclinical carotid markers that predict cardiovascular events. Methods 203 community-dwelling adults (Northern Manhattan Study, age: 68±11, 50–93 yrs) had serum measurements (calcium, phosphorus, 25-hydroxyvitamin D [25OHD], 1,25-dihydroxyvitamin D, PTH) and carotid ultrasound (plaque presence, number, maximal carotid plaque thickness [MCPT], intima-media thickness [IMT]). Results Adjusting for cardiovascular risk factors, plaque number was associated with phosphorus levels (β=0.39 per unit increase; p=0.02) and calcium-phosphorus product (β=0.36 per 10 unit increase; p=0.03). In those with plaque (N=116; 57%), the association of plaque number with phosphorus and calcium-phosphorus product persisted. In addition, 25OHD was inversely associated with both IMT (β= −0.01 per 10 ng/ml increase; p=0.05) and MCPT (β= −0.10 per 10 ng/ml increase; p=0.03). In a model containing traditional cardiac risk factors and indices of mineral metabolism, 25OHD accounted for 13% of the variance in both IMT and MCPT. Calcium, PTH, and 1,25-dihydroxyvitamin D levels were not associated with carotid measures. Conclusion After adjusting for cardiovascular risk factors and renal function, serum phosphorus and calcium-phosphorus product were associated with greater burden of subclinical carotid atherosclerosis. Low 25OHD levels were associated with increased IMT and MCPT in those with plaque, and 25OHD contributed in a robust manner to the variance in both. These results confirm and extend data on the association of low vitamin D levels with subclinical carotid atherosclerosis. The precise nature of this association and the optimum levels of vitamin D for vascular health remain to be elucidated.

PTX reduced LVM in PHPT, and higher preoperative PTH levels were associated with greater improvements. Because the benefit was limited to short-term studies and PHPT disease severity was not independent of study design, further work is needed to clarify the factors that influence the change in LVM and whether the benefit persists beyond 6 months after PTX. Although the clinical significance of the LVM improvement is unclear, these data indicate that PTH may underlie increased LVM in PHPT.