Is it safe to take Gelatin, vitamin C, and Biotin capsules during pregnancy?

Before becoming pregnant I had a problems with my hair. My hair was falling like mad crazy. My hair was everywhere in the house, floors,bed etc. So i started taking Gelatin 1300 MG, Biotin 5000mcg,

Vitamin C1000 MG, and I changed to natural shampoo and that resolved the problem. Now I'm pregnant and I had to start taking the prenatal vitamins and eating what I'm supposed to be eating. But when it comes to pregnancy my skin is not so blessed when it comes to not getting stretch marks. This is my 2nd pregnancy and I'm wonder if I can still take my supplements without hurting the baby. I don't want to become bald and have more stretch marks. I use coconut oil all over my body but I'm afraid this will not be enough and won't help with my hair falling off. Anyone can help?