Vitamins A, C, E + Glycine, Leucine, and Taurine: 6 Common Vitamins + Amino Acids to Help W/ Muscle + Tendon Injury

You may, in fact, already take these.

In a recent systematic review, Christopher Tack et al. have recently analyzed "The Physiological Mechanisms of Effect of Vitamins and Amino Acids on Tendon and Muscle Healing" (Tack 2017). In the corresponding paper in International Journal of Sport Nutrition and Exercise Metabolism, the scientist from the University of Hertfordshire, list six amino acids and vitamins (and their respective combinations) as potential tools to accelerate, help, and support soft tissue, specifically muscle and tendon healing.
The scientists came up with this list by digging through the standard databases, i.e. BSCO, PUBMED, Science Direct, Embase Classic/ Embase, and MEDLINE looking for terms including “vitamins”, “amino acids”, “healing”, “muscle” and “tendon”. If you've used these databases, you will not be surprised that the scientists' initial search yielded 479 citations. "Luckily", 466 of these could be removed after a cursory look at the methodology section and identifying those studies with non-randomised design.

This process left the authors with relevant randomised human and animal studies investigating all supplement types/ forms of administration. A list of papers, the scientists further processed using the Cochrane risk of bias tool and/or the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) risk of bias tool for human and animal studies, respectively.

Eventually, twelve studies met criteria for inclusion: 8 examined tendon healing, 4 examined muscle healing. All studies used animal models, except 2 human trials using a combined integrator (=combination supplement).

A narrative synthesis was performed via content analysis of demonstrated statistically significant effects, and thematic analysis of proposed physiological mechanisms of intervention. And here's the gist:

• Vitamin C + taurine demonstrated indirect effects on tendon healing through anti-oxidant activity, most pronounced upon local injection, but also w/ oral suupplementation
• Vitamin A + glycine showed direct effects on extra-cellular matrix tissue synthesis, both as a facilitating factor and as a substrate
• Vitamin E shows an anti-proliferative influence on collagen deposition where you certainly don't want it: in your heart muscle for-example
• Leucine directly influences signaling pathways to promote muscle protein synthesis and all sorts of proteins that are associated w/ muscle damage, whey, a high leucine protein source has also been found to promote collagen synthesis post-workout

Remember vitamin C + collagen from "100% Increase in Exercise-Induced Collagen Synthesis With Cheap, Yet Effective 15g Gelatin + 200mg Vitamin C Stack" (read it)?
If the former applies to you, you obviously are a seasoned SuppVersity veteran, which is why it's unlikely that you'll be surprised to see any of these six vitamins/aminos on the list.

Table 1: Overview of effects of vitamin/amino acid supplements on tendon and muscle (Tack 2017).

With distinct mechanisms, possible stacks could/should contain all four previously mentioned pairs, as their effects can be - as the overview in Table 1 shows - synergistic; with the most potent stack being a combination of glycine, vitamin C, and taurine and extra leucine for muscular health.
References:

• Farup, Jean, et al. "Whey protein hydrolysate augments tendon and muscle hypertrophy independent of resistance exercise contraction mode." Scandinavian journal of medicine & science in sports 24.5 (2014): 788-798.
• Oliva, Francesco, et al. "Thyroid hormones and tendon: current views and future perspectives. Concise review." Muscles, ligaments and tendons journal 3.3 (2013): 201.
• Russell, Jean E., and Paul R. Manske. "Ascorbic acid requirement for optimal flexor tendon repair in vitro." Journal of orthopaedic research 9.5 (1991): 714-719.
• Tack, Christopher, Faye Shorthouse, and Lindsy Kass. "The Physiological Mechanisms of Effect of Vitamins and Amino Acids on Tendon and Muscle Healing: A Systematic Review." International journal of sport nutrition and exercise metabolism (2017): 1-44.