B vitamins are not interchangeable with an energy boost
Vitamin B12 is essential to normal body function, and deficiency can cause fatigue and other symptoms. But the NIH Office of Dietary Supplements reports no performance benefit from B12 supplementation in the absence of a nutritional deficit.[2]
The distinction is practical: correcting a documented deficiency is a specific treatment goal. Trying to feel better after repeated overnight flights is a different claim and needs its own evidence.
NAD+ has a biological role; product benefits need separate evidence
NAD+ is a coenzyme involved in energy metabolism and other cellular processes. Research into its role in aging does not establish that a particular injection will reverse jet lag, restore stamina or improve the effects of a demanding travel schedule. Studies of biology, oral precursors and injectable preparations are not interchangeable.[3]
Compounded NAD+ injections also raise product-quality questions. FDA has reported adverse events including severe chills, shaking, vomiting and fatigue after NAD+ injectable drugs, and has warned compounders about ingredients unsuitable for sterile preparation.[4]
Start with the pattern of fatigue
An assessment can distinguish sleepiness, reduced endurance and persistent exhaustion. Travel dates, sleep opportunity, medication changes and whether fatigue continues at home give the symptom useful context. Ongoing fatigue has possible causes beyond a nutrient deficiency, including sleep disorders, anemia and thyroid disease.[1]
