Most pharmacies stock salt tablets, you can call the pharmacies near you to see if they have any in stock. You don't need a prescription for them. They come in different mg tablets. When my 4 year-old daughter doesn't eat well in a day, we use the tablets to provide more salt. She was having headaches a lot in the mornings. She calls the tablets "white headache tablets" and will say she needs one of those when she has a headache. I'm still not sure "low salt" is the reason for the headaches though, it could be she needs a drink (fluids) or gatorade-type drink (for glucose).