The Impact of Vitamin D, Calcium, Protein Supplementation, and Physical Exercise on Bone Metabolism After Bariatric Surgery: The BABS Study

Abstract

Laparoscopic Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) are common and effective methods to treat severe obesity, but these procedures can adversely influence bone metabolism and areal bone mineral density (aBMD). This was a prospective 24-month single-center interventional two-arm study in 220 women and similarly aged men (median age 40.7 years) with a body mass index (BMI) >38 kg/m 2 after RYGB and SG procedures. Patients were randomized into: 1) an intervention group receiving: 28,000 IU cholecalciferol/wk for 8 weeks before bariatric surgery, 16,000 IU/wk and 1000 mg calciummonocitrate/d after surgery, daily BMI-adjusted protein supplementation and physical exercise (Nordic walking, strength perseverance, and equipment training); 2) a non-intervention group: no preoperative loading, nutritional supplementation, or obligatory physical exercise. At study endpoint, when comparing the intervention group to the non-intervention group, the relative percentage changes of serum levels of sclerostin (12.1% versus 63.8%), cross-linked C-telopeptide (CTX, 82.6% versus 158.3%), 25-OH vitamin D (13.4% versus 18.2%), phosphate (23.7% versus 32%, p < 0.001 for all), procollagen type 1 amino-terminal propeptide (P1NP, 12% versus 41.2%), intact parathyroid hormone (iPTH, -17.3% versus -7.6%), and Dickkopf-1 (-3.9% versus -8.9%, p < 0.05 for all) differed. The decline in lumbar spine, total hip and total body aBMD, changes in BMI, lean body mass (LBM), as well as changes in trabecular bone score (TBS) values (p < 0.005 for all) were less, but significantly, pronounced in the intervention group. We conclude that vitamin D loading and ongoing vitamin D, calcium, and BMI-adjusted protein supplementation in combination with physical exercise decelerates the loss of aBMD and LBM after bariatric surgery. Moreover, the well-known increases of bone turnover markers are less pronounced.

Obesity and bone metabolism

“…Also, as with diet-induced weight loss, there have been some attempts to attenuate bone loss with physical exercise. In a 24-month, randomized, controlled study evaluating the effects of an intervention including a combination of high vitamin D and calcium supplementation with exercise post-bariatric surgery, the intervention group had attenuated increase in bone turnover markers and less pronounced bone loss as compared with the non-intervention group [128]. In another study, a weightbearing and aerobic exercise intervention program postbariatric surgery resulted in less pronounced bone loss which was associated with preservation of muscle mass [129].…”

Decline in Bone Mass During Weight Loss: A Cause for Concern?

“…Bariatric surgery patients, who are predominantly premenopausal women, routinely lose ∼30% of preoperative weight, and dramatic skeletal changes are well documented in prospective cohort studies, particularly after Roux‐en‐Y gastric bypass surgery. Reported changes include BMD decreases of 5% to 10% at the hip by DXA, decreases of 5% to 7% at the spine by QCT, and alterations in trabecular and cortical microarchitecture associated with decreased bone strength . Bariatric surgery not only causes more extreme mechanical unloading of the skeleton and more pronounced changes in adipokines than nonsurgical weight loss, but also, particularly for Roux‐en‐Y gastric bypass, induces substantial changes in gut‐secreted hormones such as peptide YY and leads to malabsorption of nutrients including calcium .…”

“…When dietary strategies have been considered, both higher calcium intake and, separately, higher protein intake have attenuated declines in BMD during caloric restriction. (In the bariatric surgery population, a multipronged intervention of exercise, calcium, vitamin D, and protein supplementation was recently shown to attenuate postoperative declines in BMD …”

Proceedings of the 2017 ASPEN Research Workshop—Gastric Bypass: Role of the Gut

“…Studies have demonstrated that sufficient intake of protein and iron, can realistically be obtained from diet especially if it is nutrient dense 115,141 . Use of dietary supplements is also an effective way to manage status of protein 142 , calcium, iron 141,143 , and vitamins D 115 and B 12 144 after gastric bypass. For treatment of deficiencies, although clinical trial are limited, data suggest that high-dose supplementation of iron 145 , vitamins D 142,146 and B 12 and protein 117 is effective.…”

“…Use of dietary supplements is also an effective way to manage status of protein 142 , calcium, iron 141,143 , and vitamins D 115 and B 12 144 after gastric bypass. For treatment of deficiencies, although clinical trial are limited, data suggest that high-dose supplementation of iron 145 , vitamins D 142,146 and B 12 and protein 117 is effective. Taken together, since oral ingestion of food and supplements can be used to prevent and treat malnutrition, this suggests that sufficient capacity of the gut remains for digestion and absorption of micronutrients after surgery.…”