Effects of a short course of oral phosphate treatment on serum parathyroid hormone (1?84) and biochemical markers of bone turnover: A dose-response study

Abstract

To investigate the possible use of oral phosphate as an activator of bone remodeling in coherence treatment of osteoporosis, 82 postmenopausal females, aged 50-75 years, were randomized to treatment with oral phosphate (750, 1500, or 2550 mg/day) or placebo for 7 days and followed for 4 months thereafter. All patients had sustained at least one previous fracture of the distal forearm and had a bone mineral content of the contralateral forearm or bone mineral density of the lumbar spine lower than normal mean for age. Urinary phosphate/creatinine ratio increased in a dose-dependent fashion during treatment (P less than 0.001), whereas no significant changes were seen in serum phosphate or serum calcium. Serum parathyroid hormone (PTH) rose significantly (P less than 0.05) during treatment to a maximum of 36 and 33% in the groups receiving 1500 and 2250 mg/day, respectively, whereas serum 1,25-dihydroxycholecalciferol remained unchanged. In the group receiving 1500 mg/day, mean serum osteocalcin was increased in the period from day 1 to day 28 (P less than 0.05), but no significant changes were observed in urinary hydroxyproline/creatinine ratio, or serum bone alkaline phosphatase. We conclude that a short course of oral phosphate treatment increases serum PTH considerably. Furthermore, 1500 mg/day but not 2250 mg/day increases serum osteocalcin. No clear biochemical evidence, however, of increased activation of bone remodeling could be demonstrated in either group.

Physico-chemical properties and toxic effect of fruit-ripening agent calcium carbide

“…Black and Asian people and older people may be susceptible to bone resorption as a result of high phosphorus intakes, as they are more susceptible to hypovitaminosis D, which decreases the absorption of calcium, and phosphorus has been shown to influence the parathyroid-vitamin D axis, causing an increase in serum calcium levels via bone resorption. [32][33][34] …”

Opinion of the Scientific Panel on Dietetic products, nutrition and allergies [NDA] related to the tolerable upper intake level of phosphorus

“…In the study by Brixen et al (1992) the PTH increase was not significantly different between the two highest dose groups (i.e. +1500 and +2250 mg phosphorus/day, respectively), but 3 times higher as compared to the control and low dose supplementation group (+750 mg phosphorus/day).…”

“…Osmotic diarrhoea and other mild gastrointestinal effects, including dyspepsia, nausea and vomiting have been observed as side effects in some individuals participating in supplementation studies using higher supplemental dosages (between 750-2250 mg/day; total oral intakes up to 3008 mg phosphorus/day) (Bernstein and Newton, 1966;Bell et al, 1977;Broadus et al, 1983;Grimm et al, 2001, Brixen et al, 1992Whybro et al, 1998). Details of these studies are summarized in Table 2.…”

Causal assessment of dietary acid load and bone disease: a systematic review & meta-analysis applying Hill's epidemiologic criteria for causality

“…Other reasons for excluding studies were: No numerical results presented and no response to a written request [177,178]; more than one simultaneous intervention [179-190], a simultaneous co-intervention of change of "acid" as well as other potentially bone influencing nutrients including calcium, sodium, potassium, magnesium, and/or phosphate [130,191-194], hypothesis generating studies that lack a no-intervention control group [195-197], time periods were shorter than 24 hours [198-210], did not include outcomes required in the inclusion criteria [211]; all of the subjects had a chronic medical condition [124,212-220], were on medications [221], or were in a state of weight loss [222-225], only included children [106-108,137,138,141-143,145,149,155,166,202], or only included animals [226-228]. Two studies [229,230] were subsets of included studies [56,75].…”