Clinically, multiple cohort studies support a causal link between vitamin D deficiency and AKI risk
Munn AL, Stevenson BJ, Geli MI, Riezman H
They do not produce androgenic effects
Muscle Recovery A double-blind, placebo, crossover study found that 2 g of L-carnitine had positive effects and significantly attenuated markers of purine metabolism, free radical formation, muscle tissue disruption, and muscle soreness after physical exertion.[4] A randomized, placebo-controlled study suggested L-carnitine can improve exercise tolerance and muscle strength while decreasing lactic production
doi: 10.1084/jem.192.2.295 91 AnsaldoESlaydenLCChingKLKochMAWolfNKPlichtaDRet al
The simplest way to understand the difference: Niagen helps your body make NAD+, while NAD+ is the molecule your cells actually use to produce energy and carry out essential functions