Category Archives: Vitamin C

Saturated Fat Associated with Lower Bone Density; Protein or Vitamin C No Help

Abstract

Dietary saturated fat intake is inversely associated with bone density in humans: analysis of NHANES III.

Mounting evidence indicates that the amount and type of fat in the diet can have important effects on bone health. Most of this evidence is derived from animal studies. Of the few human studies that have been conducted, relatively small numbers of subjects and/or primarily female subjects were included. The present study assessed the relation of dietary fat to hip bone mineral density (BMD) in men and women using NHANES III data (n = 14,850). Multivariate models using SAS-callable SUDAAN were used to adjust for the sampling scheme. Models were adjusted for age, sex, weight, height, race, total energy and calcium intakes, smoking, and weight-bearing exercise. Data from women were further adjusted for use of hormone replacement therapy. Including dietary protein, vitamin C, and beta-carotene in the model did not influence the outcome. Analysis of covariance was used to generate mean BMD by quintile of total and saturated fat intake for 4 sex/age groups. Saturated fat intake was negatively associated with BMD at several hip sites. The greatest effects were seen among men < 50 y old (linear trend P = 0.004 for the femoral neck). For the femoral neck, adjusted mean BMD was 4.3% less among men with the highest compared with the lowest quintile of saturated fat intake (BMD, 95% CI: highest quintile: 0.922 g/cm2, 0.909-0.935; lowest quintile: 0.963 g/cm2, 95% CI: 0.950-0.976). These data indicate that BMD is negatively associated with saturated fat intake, and that men may be particularly vulnerable to these effects.

Corwin RL, Hartman TJ, Maczuga SA, Graubard BI
J. Nutr. Jan 2006
PMID: 16365076 | Free Full Text

Vitamins C + E, or Exercise, Prevent Bone Loss in Women

Abstract

Effect of antioxidants combined to resistance training on BMD in elderly women: a pilot study.

We determined the effect of antioxidants and resistance training on bone mineral density of postmenopausal women. After 6 months, we observed a significant decrease in the lumbar spine BMD of the placebo group while other groups remained stable. Antioxidants may offer protection against bone loss such as resistance training.
The purpose of this pilot study was to determine the effects of antioxidant supplements combined to resistance training on bone mineral density (BMD) in healthy elderly women.
Thirty-four postmenopausal women (66.1 +/- 3.3 years) were randomized in four groups (placebo, n = 7; antioxidants, n = 8; exercise and placebo, n = 11; and exercise and antioxidants, n = 8). The 6-month intervention consisted in antioxidant supplements (600 mg vitamin E and 1,000 mg vitamin C daily) or resistance exercise (3x/week). Femoral neck and lumbar spine BMD (DXA) and dietary intakes (3-day food record) were measured before and after the intervention. A repeated measure ANOVA and non-parametric Mann-Whitney U tests were used.
We observed a significant decrease in the placebo group for lumbar spine BMD (pre, 1.01 +/- 0.17 g/cm(2); post, 1.00 +/- 0.16 g/cm(2); P < 0.05 respectively) while it remained stable in all other groups. No changes were observed for femoral neck BMD.
Antioxidant vitamins may offer some protection against bone loss in the same extent as resistance exercise although combining both does not seem to produce additional effects. Our results suggest to further investigate the impact of antioxidant supplements on the prevention of osteoporosis.

Chuin A, Labonté M, Tessier D, Khalil A…
Osteoporos Int Jul 2009
PMID: 19020919

Vitamin C Inhibits Osteoclasts in Rats Fed a High-Cholesterol Diet

Abstract

Vitamin C intake inhibits serum lipid peroxidation and osteoclast differentiation on alveolar bone in rats fed on a high-cholesterol diet.

A high-cholesterol diet stimulates osteoclast differentiation, which may be induced by increased serum lipid peroxidation. The inhibition of serum lipid peroxidation by vitamin C may offer beneficial effects on osteoclast differentiation including increased expression of receptor activator of nuclear factor (NF)-kappaB ligand (RANKL) and NF-kappaB. This study investigated the effects of vitamin C intake on RANKL and NF-kappaB expression in periodontal tissue of rats fed a high-cholesterol diet.
Twenty-four rats (8 weeks old) were divided into four groups: a control group (fed a regular diet) and three experimental groups (fed a high-cholesterol diet supplemented with 0, 1 and 2 g/l vitamin C/day) in this 12-week study. Vitamin C was provided by its addition to drinking water. As an index of serum lipid peroxidation, hexanoyl-lysine (HEL) level was determined by a competitive enzyme-linked immunosorbent assay method. Immunohistological analysis was performed to evaluate RANKL and NF-kappaB expression on the alveolar bone surface. The number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts was also counted.
Feeding a high-cholesterol diet increased not only the serum HEL level but also the number of TRAP-positive osteoclasts on the alveolar bone surface, with an increase in RANKL and NF-kappaB expression on alveolar bone surface. Intake of vitamin C reduced the serum HEL level and osteoclast differentiation, with decreasing RANKL and NF-kappaB expression.
Vitamin C intake could suppress osteoclast differentiation, including RANKL and NF-kappaB expression on the alveolar bone surface, by decreasing serum lipid peroxidation in rats fed a high-cholesterol diet.

Sanbe T, Tomofuji T, Ekuni D, Azuma T…
Arch. Oral Biol. Mar 2009
PMID: 19110235

Vitamin C Increases Collagen Synthesis of Osteoblasts

Abstract

Rab GTPase mediated procollagen trafficking in ascorbic acid stimulated osteoblasts.

Despite advances in investigating functional aspects of osteoblast (OB) differentiation, especially studies on how bone proteins are deposited and mineralized, there has been little research on the intracellular trafficking of bone proteins during OB differentiation. Collagen synthesis and secretion is the major function of OBs and is markedly up-regulated upon ascorbic acid (AA) stimulation, significantly more so than in fibroblast cells. Understanding the mechanism by which collagen is mobilized in specialized OB cells is important for both basic cell biology and diseases involving defects in bone protein secretion and deposition. Protein trafficking along the exocytic and endocytic pathways is aided by many molecules, with Rab GTPases being master regulators of vesicle targeting. In this study, we used microarray analysis to identify the Rab GTPases that are up-regulated during a 5-day AA differentiation of OBs, namely Rab1, Rab3d, and Rab27b. Further, we investigated the role of identified Rabs in regulating the trafficking of collagen from the site of synthesis in the ER to the Golgi and ultimately to the plasma membrane utilizing Rab dominant negative (DN) expression. We also observed that experimental halting of biosynthetic trafficking by these mutant Rabs initiated proteasome-mediated degradation of procollagen and ceased global protein translation. Acute expression of Rab1 and Rab3d DN constructs partially alleviated this negative feedback mechanism and resulted in impaired ER to Golgi trafficking of procollagen. Similar expression of Rab27b DN constructs resulted in dispersed collagen vesicles which may represent failed secretory vesicles sequestered in the cytosol. A significant and strong reduction in extracellular collagen levels was also observed implicating the functional importance of Rab1, Rab3d and Rab27b in these major collagen-producing cells.

Nabavi N, Pustylnik S, Harrison RE
PLoS ONE 2012
PMID: 23050002 | Free Full Text

Vitamin C Reverses Bone Loss in Rats

Abstract

Evaluation of erythrocyte deformability in experimentally induced osteoporosis in female rats and the effects of vitamin C supplementation on erythrocyte deformability.

The aim of this study was to evaluate the possible variations in antioxidant enzymes, lipid peroxidation and erythrocyte deformability in experimentally induced osteoporosis in female rats and to assess the effects of vitamin C supplementation on those variations.
A total of 20 female Wistar Albino Rats were randomized into the three groups as controls (Group C, n = 6), ovariectomized rats (Group O, n = 7) and ovariectomized rats receiving vitamin C supplementation (Group OVC, n = 7). After the surgical procedure of ovariectomy, group OVC received 1 g ascorbic acid in 500 mL water daily. After 100 days following the ovariectomy, bone mineral density (BMD) was measured by using dual-energy X-ray absorptiometry.
BMD was significantly lower in the group O than in the group C (p = 0.015), whereas it was significantly higher in the group OVC than in the group O (p = 0.003). MDA activity was significantly higher in the group O than in the group C (p = 0.032), whereas it was significantly lower in the group OVC than in the group O (p = 0.025). SOD activity was significantly higher in the group O than in the group C (p = 0.032). Erythrocyte deformability was significantly higher in the group O than in the group C and OVC (p = 0.008, p = 0.021, respectively).
Erythrocyte deformability may show negative variations, suggesting a causative role in disruption of blood flow and tissue perfusion, which also negatively affect bone metabolism. Vitamin C supplementation seems to reverse those negative effects of variations in erythrocyte deformability. However, our preliminary results should be confirmed in more experimental studies and clinical trials (Tab. 3, Ref. 28).

Arslan A, Aydin G, Keles I, Fm C…
Bratisl Lek Listy 2011
PMID: 22180984

Vitamin C + β-Cryptoxanthin May Increase Bone Density in Post-Menopausal Women

Abstract

Dietary patterns of antioxidant vitamin and carotenoid intake associated with bone mineral density: findings from post-menopausal Japanese female subjects.

Recent studies show that antioxidants may reduce the risk of osteoporosis. This study showed the associations of bone mineral density with dietary patterns of antioxidant vitamins and carotenoids. The findings suggest the combination of vitamin C and β-cryptoxanthin intakes might provide benefit to bone health in post-menopausal Japanese female subjects.
Recent epidemiological studies show antioxidants may reduce the risk of osteoporosis, but little is known about the dietary patterns of antioxidant vitamin and carotenoid intakes and their relation with bone mineral density (BMD).
A total of 293 post-menopausal female subjects who had received health examinations in the town of Mikkabi, Shizuoka Prefecture, Japan, participated in the study. Radial BMD was measured using dual-energy X-ray absorptiometry. Dietary intakes of antioxidant vitamins and carotenoids were assessed by using a validated food-frequency questionnaire. Dietary patterns were identified on a selected set of antioxidants through principal component factor analysis.
Three dietary patterns were identified. The “retinol” pattern, characterized by notably high intakes of preformed retinol, zeaxanthin, and vitamin E, was positively associated with the risk for low BMD. In contrast, the “β-cryptoxanthin” pattern, characterized by notably high intakes of β-cryptoxanthin and vitamin C, was negatively associated with low BMD. The odds ratios for low BMD in the highest tertiles of dietary intakes of preformed retinol, vitamin C, and β-cryptoxanthin against the lowest tertiles were 3.22 [95% confidence interval (CI), 1.38-7.51], 0.25 (CI, 0.10-0.66), and 0.40 (CI, 0.17-0.92), respectively, after adjustments for confounders. However, negative associations of vitamin C and β-cryptoxanthin with low BMD were not significant after further adjustment for intake of β-cryptoxanthin or vitamin C, respectively. Higher intakes of both vitamin C and β-cryptoxanthin were significantly associated with low BMD (P < 0.05).
The combination of vitamin C and β-cryptoxanthin may be associated with radial BMD in post-menopausal Japanese female subjects.

Sugiura M, Nakamura M, Ogawa K, Ikoma Y…
Osteoporos Int Jan 2011
PMID: 20480147

Vitamin C + Calcium is Associated with Increased Bone Mass in Postmenopausal Women

Abstract

The relation of dietary vitamin C intake to bone mineral density: results from the PEPI study.

Ascorbic acid is a required cofactor in the hydroxylations of lysine and proline necessary for collagen formation; its role in bone cell differentiation and formation is less well characterized. This study examines the cross-sectional relation between dietary vitamin C intake and bone mineral density (BMD) in women from the Postmenopausal Estrogen/Progestin Interventions Trial. BMD (spine and hip) was measured using dual energy X-ray absorptiometry (DXA). The PEPI participants (n = 775) included in this analysis were Caucasian and ranged in age from 45 to 64 years. At the femoral neck and total hip after adjustment for age, BMI, estrogen use, smoking, leisure physical activity, calcium and total energy intake, each 100 mg increment in dietary vitamin C intake, was associated with a 0. 017 g/cm2 increment in BMD (P = 0.002 femoral neck; P = 0.005 total hip). After adjustment, the association of vitamin C with lumbar spine BMD was similar to that at the hip, but was not statistically significant (P = 0.08). To assess for effect modification by dietary calcium, the analyses were repeated, stratified by calcium intake (>500 mg/day and </=500 mg/day). For the femoral neck, women with higher calcium intake had an increment of 0.0190 g/cm2 in BMD per 100 mg vitamin C (P = 0.002). No relation between BMD and vitamin C was evident in the lower calcium stratum. Similar effect modification by calcium was observed at the total hip: the beta coefficient in the higher calcium stratum was similar to that for the total sample (beta = 0.0172, P = 0.01), but no statistically significant relation between total hip BMD and vitamin C was found in the lower calcium subgroup. Although the relation between vitamin C and lumbar spine BMD was of marginal statistical significance in the total sample, among women ingesting higher calcium, a statistically significant association was observed (beta = 0.0199, P = 0.024). These data are consistent with a positive association of vitamin C with BMD in postmenopausal women with dietary calcium intakes of at least 500 mg.

Hall SL, Greendale GA
Calcif. Tissue Int. Sep 1998
PMID: 9701620

Lipoic Acid + Vitamin C Inhibit Bone Resorption in Rats

Abstract

Therapeutic effects of alpha lipoic acid and vitamin C on alveolar bone resorption after experimental periodontitis in rats: a biochemical, histochemical, and stereologic study.

Alpha lipoic acid (ALA) and vitamin C (Vit-C) are very important and powerful antioxidants that have been used for the treatment of many diseases. The present study aims to investigate the role of ALA and Vit-C substances in the treatment of alveolar bone resorption in periodontal diseases.
Thirty-six male Wistar albino rats were randomly divided into four groups as follows: 1) control rats; 2) rats with experimental periodontitis (PED); 3) rats with PED treated with ALA (ALA); and 4) rats with PED treated with ALA+Vit-C (ALA+Vit-C). PED was simulated by placing ligatures around the neck of teeth for 5 weeks. After ligature removal, the PED group was given a single intragastric dose of 1 mL saline, and the ALA and ALA+Vit-C groups were treated with an intragastric dose of 50 mg/kg ALA and ALA+Vit-C for 15 days, respectively. Levels of serum bone alkaline phosphatase (B-ALP) and myeloperoxidase (MPO) activity in gingival tissues were analyzed. To evaluate the osteoclast activation, expression of activated receptor activator nuclear factor-kappa B ligand (RANKL) and bone density index (BDI) were determined stereologically in the bone sections obtained from the mandibles of the rats.
The results showed statistically significant differences between the PED group and groups treated with antioxidant according to B-ALP, MPO, RANKL, and BDI values (P <0.05). ALA and ALA+Vit-C treatments showed beneficial effects on the mesial/distal periodontal bone support at the ligature-induced periodontitis tooth areas.
This study shows that ALA and Vit-C treatment provides therapeutic effects on inhibition of alveolar bone resorption and periodontal tissue destruction.

Akman S, Canakci V, Kara A, Tozoglu U…
J. Periodontol. May 2013
PMID: 22702517