Are there any nutritional and/or herbal supplements that help those with EDS?

There are no studies to refer to about what effects nutrition, vitamins, and herbal supplements have on the EDS patient. But, many EDS patients have had some benefits from certain diets, vitamins (especially Vitamin C), Zinc, Magnesium, Glucosamine, Chondroitin, MSM, etc. This is an individual choice. Before starting any new treatment or supplements always seek a consultation and the advice from your medical doctors concerning the effects of these supplements. Intracellular erythrocyte magnesium (RBC Mg) for muscle cramps and migraines were more frequent in Mg-deficient patients. Low potassium is likely to cause muscle weakness and even paralysis. Coghlan HC, Natello G. "Erythrocyte magnesium in symptomatic patients with primary mitral valve prolapse: relationship to symptoms,  mitral leaflet thickness, joint hypermobility and autonomic regulation." Magnes Trace Elem. 1991-92;10(2-4):205-14