High Serum Retinol as a Relevant Contributor to Low Bone Mineral Density in Postmenopausal Osteoporotic Women

Abstract

There is controversial information about the impact of vitamin A on bone. Some epidemiological studies show that excessive intake of vitamin A, or an excess of serum vitamin A, has related with adverse impact on bone mass; however, other studies did not find these links, and some authors have proposed that this vitamin might promote a better bone health. The present work aims to contribute to clarify the real role of vitamin A in bone tissue. For this purpose, a cross-sectional study of 154 osteoporotic non-treated postmenopausal women (> 65 years old) was carried out. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. We assessed concentrations of serum retinol, osteocalcin, parathyroid hormone, alkaline phosphatase, calcium, and phosphorus. We also studied demographic and anthropometric parameters. Spearman's correlations between retinol levels and other variables found negative correlations with BMD in both lumbar spine (R = - 0.162, P < 0.01) and femoral neck (R = - 0.182, P < 0.01), as well as alkaline phosphatase (R = - 0.110; P < 0.05) and phosphorus (R = - 0.110; P < 0.05). A positive correlation between retinol and fertile window was observed (R = 0.158; P < 0.01). After multivariable adjustment, we still found a negative correlation between serum retinol and BMD, both at the lumbar spine (R = - 0.210; P < 0.01) and at the femoral neck (R = - 0.324, P < 0.001). It is concluded that elevated serum-retinol levels are associated with an increased risk of low bone mass and thus with osteoporotic fractures. Therefore, osteoporosis-risk assessment should include quantification of serum metabolite of vitamin A.

Nutrients in the Prevention of Osteoporosis in Patients with Inflammatory Bowel Diseases

“…In fact, vitamin A or beta-carotene supplementation within a 15-year period did not increase the risk of bone fractures [ 82 ]. The retinol serum level correlated negatively with the BMD of the lumbar spine and femoral neck in postmenopausal women [ 83 ]. A meta-analysis showed that a high vitamin A level but not beta-carotene intake increased the risk of a femoral neck fracture.…”

Role of Dietary Intake and Serum 25(OH)D on the Effects of a Multicomponent Exercise Program on Bone Mass and Structure of Frail and Pre-Frail Older Adults

“…Although this micronutrient has been less studied, a possible explanation could be that it plays a role in inflammation, inhibiting osteoclastic activity by complex pathways described elsewhere [ 44 , 45 ]. Otherwise, in the present study, it has been observed that dietary vitamin A has been also associated to higher decreases in bone parameters; vitamin A is a potential antioxidant with multiple benefits in the ageing process but which can produce breakdown effects in the bone if it is consumed in an excess [ 46 ]. The mean intake of our cohort was above the recommended levels, but it did not reach the excess threshold.…”

Circulating serum level of retinoic acid and hip fractures among postmenopausal women

“…Similarly, another study found that elevated serum-retinol levels are associated with an increased risk of low bone mass and, thus, with osteoporotic fractures. 24 However, no association between vitamin A or retinol intake and the risk of hip or total fractures was observed in postmenopausal women in the study by Caire-Juvera et al 25 Similarly, Holvik et al 26 found no evidence of an adverse effect of high serum retinol on hip fracture, and Vestergaard et al 27 suggested that risk of fracture was not associated with vitamin A analogue treatment. Furthermore, another study suggested that inverse U-shaped association of retinol intake with BMD and bone maintenance observed in this cohort raises the concern that either too little or too much retinol may adversely affect bone health.…”

“…A biochemical marker of retinol intake in relation to fracture risk had been reported in a cohort study; this study reported a 64% increase in risk of any osteoporotic fracture for men in the top quintile of serum retinol relative to those in the middle quintile. Similarly, another study found that elevated serum‐retinol levels are associated with an increased risk of low bone mass and, thus, with osteoporotic fractures . However, no association between vitamin A or retinol intake and the risk of hip or total fractures was observed in postmenopausal women in the study by Caire‐Juvera et al Similarly, Holvik et al found no evidence of an adverse effect of high serum retinol on hip fracture, and Vestergaard et al suggested that risk of fracture was not associated with vitamin A analogue treatment.…”