13 yrs old has lost weight recently, she is eating 1/2 grapefruit and cereal with lactose milk in the morning, an apple, bottle of water/energy bar for lunch, a full meal for dinner with whole wheat, fish vegetable and glass of milk and is taking anti-inflammatory till April (Enthesitis-Achilles tendonitis

It seems much better but, recently she has been getting colored dots in her vision that makes her feel faintish and warm when she rises from lying down or from bending over suddenly. It happens only on certain days then comes and goes?