应该高度关注维生素D在人体中的广泛生物学作用

More attention should be paid to the comprehensive biological effects of vitamin D on human beings

维生素D是一种脂溶性维生素。其在人体内经过肝脏和肾脏羟化后成为一种重要的激素,即1,25-二羟维生素D3。这种激素不仅促进肠道钙磷的吸收,维护骨骼的健康,还可刺激人体内的巨噬细胞分泌一种抗菌蛋白（cathelicidin）,能有效吞噬包括病毒和细菌在内的多种微生物。适量补充维生素D对于维护人体健康十分重要。

Vitamin D is one of the fat-soluble vitamins which, eventually through activation in the liver and kidneys within the human body, becomes an important hormone——1,25-dihydroxyvitamin D3. Not only may 1,25-dihydroxyvitamin D3 promote calcium and phosphate absorption by the intestine, but also stimulate the macrophages to secrete a protein（cathelicidin） which is able to digest the microbacterias, including viruses and bacteria, playing an antiinfective effects. Theofore, a proper supplementation of vitamin D would be beneficial for human health.