Abstract: The dietary supplements of various embodiments comprise a water-soluble vitamin component, an oil-soluble vitamin component, magnesium or derivatives thereof, a primary polyphenolic compound, a secondary polyphenolic compound, and an omega-3-phospholipid complex. The methods include maintaining health, maintaining brain health and reducing the risk or rate of neurodegeneration or cognitive decline. Methods, including algorithms, for systematically determining a dietary supplement are also described.