Calcium metabolism and vitamin D in the extreme longevity

Abstract

Skeletal remodelling is a continuous process during life and is still active also in extreme senescence. In the elderly, bone resorption often prevails over bone formation, causing bone loss and fragility. Elderly subjects are exposed to the risk of fractures, and loss of self-sufficiency, if considering that the proximal femur is the most frequently involved site. Bone remodelling can maintain circulating calcium within physiological ranges, at the expense of a substantial loss of this ion from the skeleton, particularly during senescence. Calcium metabolism is regulated at cellular/molecular level by a network of cytokines, growth factors, systemic hormones that act on bone in paracrine/autocrine/ systemic fashion. Among the molecules involved in bone metabolism, parathyroid hormone (PTH) and vitamin D present some peculiar aspects during senescence. The osteometabolic features in a consistent group of centenarians have been evaluated. It results that a severe hypovitaminosis D was present in 99 out of 104 centenarians (25-OH vitamin D below 5 nmol/L), and that it plays an important role as a factor inducing a vicious circle involving hypocalcemia, secondary hyperparathyroidism, together with biochemical features indicating a consistent bone loss. Serum C-terminal cross-linking telopeptide, a specific marker of bone resorption was elevated in 92% of these subjects. Moreover, it has been found that several femoral fractures had occurred after 90 years of age. These data offer a rational for the possible prevention of elevated bone turnover, bone loss and consequently the reduction of osteoporotic fractures and fractures-induced disability, in the oldest olds, through the simple supplementation with calcium and vitamin D.

Vitamin B12 deficiency in African American and white octogenarians and centenarians in Georgia

“…The prevalence of vitamin D insufficiency in centenarians was higher than in octogenarians, but the overall vitamin D status of these US centenarians was better than observed for Italian centenarians (10,11). Other major findings include the similar prevalence of vitamin D insufficiency in men and women, the large impact of race and supplement use, the lack of benefit of the reported dairy food intake, and the similar vitamin D status in those residing in the community and in skilled nursing facilities.…”

“…In a study of centenarians from Italy, 25(OH)D concentrations were 78 nmol/L in one participant receiving vitamin D injections, averaged 16 nmol/L in four centenarians with detectable concentrations, and was not detectable in the remaining 99 individuals (10,11). The high prevalence of vitamin D deficiency was attributed to several factors including rainy weather, not going outside, and lack of vitamin D-fortified foods in Italy.…”

“…However, common nutritional problems in older adults, such as poor vitamin D status, have received little attention in centenarians. A study from Italy suggested that the vast majority of centenarians may have vitamin D deficiency (10, 11), but to our knowledge there are no reported studies of vitamin D status in centenarians in the United States.…”

A potential link between phosphate and aging—Lessons from Klotho-deficient mice

“…1: Klotho −/− mouse, 2: Mouse, 3: Rat, 4: Hamster, 5: Gerbil, 6: Nutria, 7: Rabbit, 8: Guinea pig, 9: Sheep, 10: Squirrel, 11: Porcupine, 12: Naked mole rat, 13: Flying fox, 14: Bear, 15: Rhinoceros, 16: Elephant, 17: Human, 18: Human (centenarian). Serum phosphate leves are average or median values, whichever available in literatures (Asadi et al, 2007; Feldhamer et al, 2003; Field et al, 1998; Gorbunova et al, 2008; Heard et al, 2006; Holliday, 1995; Kuro-o et al, 1997; Moreau et al, 2003; Munson et al, 1998; Passeri et al, 2008; Pugh, 2002; Ramsay, 2003; Segawa et al, 2007; Thrall et al, 2004; Tuntasuvan et al, 2002; Yahav et al, 1993). …”

New predictive model for monitoring bone remodeling

“…Several prior studies show that nutrition (e.g., vitamin D) plays an important role in the maintenance of bones 64, 65. Vitamin D is essential in the development of an intact and strong skeleton, and it promotes bone formation and mineralization.…”