Evidence Review
What the research actually shows — mechanism, dosing, and safety for the supplements most relevant to adults 40 and older.
Also known as: creatine monohydrate, Cr, creatine phosphate
One of the most studied supplements in sports science and gerontology. Creatine supports ATP regeneration in muscle and brain tissue, with strong evidence for improving strength, training adaptation, and emerging evidence for cognitive support in older adults.
View profile →Also known as: magnesium bisglycinate, chelated magnesium
A highly bioavailable form of magnesium bound to glycine. Involved in over 300 enzymatic reactions, magnesium supports sleep quality, muscle relaxation, stress response, blood sugar regulation, and cardiovascular function. Deficiency is common in adults over 40.
View profile →Also known as: cholecalciferol, vitamin D, 25-hydroxyvitamin D
A fat-soluble vitamin that functions as a hormone, with receptors in nearly every tissue type. Deficiency affects an estimated 40% of US adults and is associated with reduced muscle function, impaired immunity, bone loss, and metabolic dysfunction. Supplementation in deficient individuals has a strong evidence base.
View profile →Also known as: menaquinone-7, MK-7, vitamin K2
A longer-acting form of vitamin K2 that helps activate proteins involved in calcium placement. It is most often used alongside vitamin D3 to support bone health while helping keep calcium out of soft tissue.
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