Если понимаешь по-английски, то вот тебе статья о слоящихся ногтях и о том, какие витамины нужно принимать, чтобы укрепить ногтевую пластину :
Splitting nails: a lack of sufficient hydrochloric acid (соляная кислота) in the stomach.
One of the things you could be missing is biotin, a B-Complex vitamin that is necessary for your body to process the fat and protein that you eat. Biotin can be destroyed by certain food processing techniques such as canning and heat curing.
You do need to make sure that you aren't exposing your nails to harsh chemicals or using too much polish remover both of which deprive your nails of moisture.
Flaxseed oil also helps.
Strengthen Nails:
To strengthen your nails, soak them in a strong infusion of horsetail (хвощ), made by pouring 0,5 L of hot water over a tablespoon of dried horsetail. Horsetail is a plant that is rich in silicon; a natural constituent of nails, hair, and collagen. You can also take an infusion of horsetail by pouring a cup of hot water over two teaspoons of horsetail, letting this steep for 15 to 20 minutes, then drinking the infusion three times a day.
Helpful Nutrition:
Weak nails: Vitamin B Complex. Biotin - 2 milligrams daily Flaxseed oil - follow directions on the label.
Develop strong nails: Amino acids, vitamin A. Black current oil (масло черной смородины).
Nail growth: Calcium/Magnesium & Vitamin D:
Top dietary sources of biotin are egg yolks, soybean flour, cereals and yeast. Cauliflower, lentils, mil, and peanut butter.
Между нами девочками говоря...