Prenatal Vitamins Drinking All At Once

Hello! Is it okay to drink all my prenatal vitamins all at once before bedtime? As far as what I have been doing, yung iron lang iniinom ko 2hrs before I drink my other vitamins such as Iberet, Calcium, Ascorbic, DHA etc. Kaso my husband asked me if its really okay to drink them all at the same time and thats when I had a second thought.. Please help?