Bowen P E, Mobarhan S, Henderson C, Stacewicz-Sapuntzakis M, Friedman H, Kaiser R
Department of Nutrition, University of Illinois, Chicago.
JPEN J Parenter Enteral Nutr. 1988 Sep-Oct;12(5):484-9. doi: 10.1177/0148607188012005484.
We have found that 12 patients requiring permanent enteral feeding secondary to cerebrovascular accident with adequate Vitamin A nutritional status had serum concentrations of various carotenoids which were only 8-17% of sex- and age-matched healthy controls. Their serum retinol levels were normal, but only 61% of their controls despite receiving two to three times the recommended daily allowance (RDA) in retinol equivalents. Commercial enteral formulas were found to contain only negligible quantities of the carotenoids and were the cause of the hypocarotenemia. To assess the ability of these patients to absorb beta-carotene, nine tube-fed patients were given 15 mg of beta-carotene (2.5 times the RDA) in a single dose. Serum concentration time curves showed that only four patients absorbed significant quantities of the beta-carotene and absorption was delayed compared to previously studied subjects taking enteral formulas as meals. These studies suggest that the efficiency of absorption of the fat soluble vitamins may be lower in tube-fed patients and that patients receiving long-term tube feeding are denied the possible protective effects of the carotenoids normally contained in the American diet.
我们发现，12名因脑血管意外而需要长期肠内喂养且维生素A营养状况良好的患者，其血清中各种类胡萝卜素的浓度仅为性别和年龄匹配的健康对照者的8%-17%。他们的血清视黄醇水平正常，但尽管摄入的视黄醇当量是推荐每日摄入量（RDA）的两到三倍，仍仅为对照者的61%。发现商业肠内配方奶粉中类胡萝卜素含量极少，这是导致低类胡萝卜素血症的原因。为了评估这些患者吸收β-胡萝卜素的能力，对9名通过鼻饲管喂养的患者单次给予15毫克β-胡萝卜素（RDA的2.5倍）。血清浓度-时间曲线显示，只有4名患者吸收了大量的β-胡萝卜素，而且与之前以肠内配方奶粉作为餐食进行研究的受试者相比，吸收延迟。这些研究表明，鼻饲患者脂溶性维生素的吸收效率可能较低，而且长期接受鼻饲的患者无法获得美国饮食中通常含有的类胡萝卜素可能带来的保护作用。
