Preventing Bone Loss and Weight Gain with Combinations of Vitamin D and Phytochemicals.

Abstract

Vitamin D (VD) & certain flavonoids have been shown to act directly on adipocytes & osteoblasts. In this study, we investigated whether a diet using a combination of flavonoids with VD would inhibit bone loss & decrease adiposity to a greater extent than control or VD alone diets. Ovariectomized (OVX) female rats (12 mo old, N=10, initial BW=240g) were given control (AIN‐93M diet alone), VD (10 IU/kg BW/d) or VD + resveratrol (R: 4, 20, or 100 mg/kg BW/d) + quercetin (Q: 20, 125 or 625 mg/kg BW/d) + genistein (G:16, 64 or 256 mg/kg BW/d) in AIN‐93M diet for 8 wk. After rats were killed, inguinal (I) & retroperitoneal (RP) fat pads were weighed & bones were collected for measurements. The high dose combination treatment (VD+R100+Q625+G256) significantly reduced BW gain (79±5 vs 62±3g, p<0.05), weight of RP+I fat pads (21.8±1 vs 19.8±0.8g, p<0.05) & RP+I fat pads as % of BW (7.5±0.4 vs 6.9±0.4%, p<0.05). Bone mineral density (BMD) & content (BMC) of femora were significantly increased by the high dose combination, although they weren't different from VD alone. However, BMD corrected for BW was significantly greater in the high dose treated group compared to both control & VD groups (4.7±0.05 vs 5.0±0.2 vs 5.6±0.2, p<0.05). We conclude that VD when combined with R, Q & G improved bone density & reduced weight gain & adiposity in OVX female rats compared to control & VD alone. Supported by the GA Research Alliance Eminent Scholar endowment (CAB).

Osteogenic effects of resveratrol in vitro: potential for the prevention and treatment of osteoporosis

“…37,38 Therefore, there is considerable interest in finding natural alternatives in foods and combining them with vitamins for further synergistic action on bone. 39 This highlights the potential of natural osteoinductive phytoestrogens such as resveratrol for the nutritional…”

Synergism between resveratrol and other phytochemicals: Implications for obesity and osteoporosis

“…Recently, resveratrol in combination with vitamin D, genistein and quercetin was tested in aged ovariectomized rats, an animal model for postmenopausal bone loss. Rats supplemented 2400 IU/kg vitamin D, 400, 2000 and 1040 mg/kg diet of resveratrol, quercetin and genistein, respectively, had reduced weight gain and adiposity without a change in food intake, compared with both phytoestrogen-free control diet and control diet plus vitamin D alone [68]. In addition, the bone marrow adipocyte density was significantly reduced with an associated decrease in osteoclasts compared with both control and vitamin D treatments.…”

Effect of resveratrol on fat mobilization

“…Several phytochemicals alone or in combination have been shown to enhance effects on promoting adipocyte apoptosis, inhibiting lipid accumulation, and promoting osteogenesis. 17,[40][41][42][43][44][45][46][47][48] Phytochemicals may act by blocking one or more targets in signal transduction pathways, by potentiating effects of other phytochemicals, or by increasing the bioavailability or half-life of other chemi-cals. For example, flavonoids such as genistein and resveratrol in combination exert an enhanced effect in 3T3-L1 adipocytes on inhibiting adipogenesis, inducing lipolysis, and triggering apoptosis.…”

“…Furthermore, trabecular bone density was markedly increased along with a decrease in bone marrow adipocyte density and a decrease in marrow osteoclast number compared to both control and vitamin D alone. 41 Resveratrol alone has been shown to stimulate osteogenesis in vitro, [49][50][51][52] and to reduce bone loss in several rodent models (Fig. 2).…”