Nielsen F H
United States Department of Agriculture, Grand Forks Human Nutrition Research Center, N. Dak.
Magnes Trace Elem. 1990;9(2):61-9.
Recent findings are reviewed indicating that changes in dietary boron and magnesium affect calcium, and thus bone, metabolism in animals and humans. In animals, the need for boron was found to be enhanced when they needed to respond to a nutritional stress which adversely affected calcium metabolism, including magnesium deficiency. A combined deficiency of boron and magnesium caused detrimental changes in the bones of animals. However, boron deprivation did not seem to enhance the requirement for magnesium. In two human studies, boron deprivation caused changes in variables associated with calcium metabolism in a manner that could be construed as being detrimental to bone formation and maintenance; these changes apparently were enhanced by low dietary magnesium. Changes caused by boron deprivation included depressed plasma ionized calcium and calcitonin as well as elevated plasma total calcium and urinary excretion of calcium. In one human study, magnesium deprivation depressed plasma ionized calcium and cholesterol. Because boron and/or magnesium deprivation causes changes similar to those seen in women with postmenopausal osteoporosis, these elements are apparently needed for optimal calcium metabolism and are thus needed to prevent the excessive bone loss which often occurs in postmenopausal women and older men.
本文综述了近期的研究发现,表明饮食中硼和镁的变化会影响钙,进而影响动物和人类的骨骼代谢。在动物中,当它们需要应对对钙代谢产生不利影响的营养应激(包括镁缺乏)时,对硼的需求会增加。硼和镁的联合缺乏会导致动物骨骼发生有害变化。然而,缺硼似乎并未增加对镁的需求。在两项人体研究中,缺硼导致与钙代谢相关的变量发生变化,这种变化可被视为对骨形成和维持有害;低膳食镁似乎会加剧这些变化。缺硼引起的变化包括血浆离子钙和降钙素降低,以及血浆总钙和尿钙排泄增加。在一项人体研究中,缺镁会降低血浆离子钙和胆固醇。由于缺硼和/或缺镁会导致与绝经后骨质疏松症女性相似的变化,因此这些元素显然是最佳钙代谢所必需的,从而有助于预防绝经后女性和老年男性经常出现的过度骨质流失。