Marsman G, Pastoor F J, Mathot J N, Theuns H M, Beynen A C
Department of Human Nutrition, Agricultural University, Wageningen, The Netherlands.
Lab Anim. 1991 Oct;25(4):330-6. doi: 10.1258/002367791780810001.
Massive, toxic doses of vitamin D have been shown to cause nephrocalcinosis in rats, but the effect of this vitamin within its range of fluctuation in commercial rat diets was unknown. Therefore, in two experiments with young female rats, the effect on nephrocalcinosis of a moderately increased level of vitamin D in the diet was studied, that is 5000 IU/kg versus the recommended concentration of 1000 IU/kg. This was done using purified diets with 0.5% (w/w) calcium and 0.04% magnesium containing either 0.2 or 0.6% phosphorus (P). Rats fed the diets containing 0.6% P showed severe kidney calcification compared to those fed the 0.2%-P diets. The level of vitamin D in the 0.2 and 0.6%-P diets did not affect kidney calcification. Bone density was increased after feeding diets containing 5000 instead of 1000 IU of vitamin D/kg. This study suggests that, within 28 days, a moderate increase of the amount of vitamin D in the diet has no influence on the development of kidney calcification. This in turn suggests that the variation in nephrocalcinosis severity and incidence seen in practice in rats fed different commercial diets is unlikely to be related to the different vitamin D concentrations in these diets. However, in rats fed such diets bone metabolism may be influenced differently.
大剂量、有毒剂量的维生素D已被证明会在大鼠中引起肾钙质沉着症，但这种维生素在商业大鼠饮食中波动范围内的影响尚不清楚。因此，在两项针对年轻雌性大鼠的实验中，研究了饮食中维生素D适度增加水平（即5000国际单位/千克，而推荐浓度为1000国际单位/千克）对肾钙质沉着症的影响。这是通过使用含钙0.5%（重量/重量）和含镁0.04%、含磷（P）0.2%或0.6%的纯化饮食来完成的。与喂食含0.2%磷饮食的大鼠相比，喂食含0.6%磷饮食的大鼠出现了严重的肾脏钙化。含0.2%和0.6%磷的饮食中维生素D水平对肾脏钙化没有影响。喂食含5000而不是1000国际单位维生素D/千克的饮食后，骨密度增加。这项研究表明，在28天内，饮食中维生素D量的适度增加对肾脏钙化的发展没有影响。这反过来表明，在实际中喂食不同商业饮食的大鼠中观察到的肾钙质沉着症严重程度和发病率的差异不太可能与这些饮食中不同的维生素D浓度有关。然而，喂食此类饮食的大鼠的骨代谢可能会受到不同的影响。
