Being a bit knowledgeable in the field of nail and hair care, I firmly believe that I have an answer for you. I have used known as nails biotin. This is not a synthetic product sold to thousands as a marketing gimmick. It is a 100% natural substance and it is a rich source of Vitamin H, and other complex sources of Vitamin B. Though there could be similar brand of biotin available in the market, I for one would strongly recommend a product known by the name Certified Biotin. From what I learn from your problem, it surely must be a case of biotin deficiency. Though you might be adding vitamin H and B-complex in your food, I would strongly urge you to go in for certifiedbiotin.com . I am sure you will find it an amazing solution and I have been able to give dozens of women the best of nail growth by using this product. It is a proven product and I am sure it will help your cause in more ways than one.