Can I safely take a combination ofL-arginine, L-citrulline, beetroot juice daily along with zinc and vitamin D3 and Magnesium Taurate? What dosages?

The combination is generally safe at standard doses, but the evidence for most of these supplements is thin, and the real risk is wasting money on effects that may not happen.

The evidence you are working with comes mostly from small, short-term studies, often in athletes or specific patient groups, not in healthy people taking these together long-term. The L-arginine and L-citrulline studies show mixed results. One 2025 trial found that a single dose of arginine plus citrulline malate did not improve aerobic, anaerobic, or CrossFit performance in trained men, though it did speed up time to peak power in a Wingate test [5]. A 2022 study found that 4 grams of arginine increased resting and post-exercise blood flow but did not improve lactate clearance or push-up endurance [4]. A 2009 study in judo athletes found no benefit from arginine on performance or nitric oxide production [2]. The 2019 watermelon juice study (funded by the National Watermelon Promotion Board) found it prevented a post-exercise blood pressure rise in women but did not affect heart rate recovery, lactate, or soreness [1]. The bottom line: these amino acids may increase blood flow modestly, but translating that into real-world performance or health benefits is not reliably shown.

For zinc, the evidence is clearer about its role in immune function and as an antioxidant, but the studies here are mostly in animals or specific deficiency states. One rat study showed zinc protected against aluminum-induced brain damage [6], and another showed it helped restore antioxidant enzymes in protein-deficient rats [7]. A 2003 review noted that zinc deficiency impairs immune cells, but high doses can also suppress immune function [9]. The key interaction to watch is with iron: a 1990 study found that iron can inhibit zinc absorption at a 2:1 molar ratio [8]. Your stack does not include iron, so that is not a concern here, but it means zinc should be taken away from any iron supplements you might take separately.

Magnesium taurate is a well-absorbed form of magnesium. The evidence here focuses on magnesium's role in vitamin D activation. A 2018 review states that the enzymes that activate vitamin D require magnesium as a cofactor [12]. This means taking vitamin D3 without adequate magnesium may be less effective. A 2020 trial protocol plans to test vitamin D3 (50,000 IU weekly) plus magnesium (250 mg daily) in obese women, but results are not yet available [11]. Magnesium also has documented benefits for blood pressure: a 1989 study in hypertensive patients found that oral magnesium supplementation (dose not specified in the record) lowered mean blood pressure from 111 to 102 mmHg and reduced triglycerides [10]. Magnesium taurate specifically has not been studied in these trials, but the magnesium content is what matters.

Vitamin D3 at typical doses (1,000-5,000 IU daily) is well-tolerated. The 50,000 IU weekly dose in the protocol is a high loading dose, not a daily maintenance dose [11]. For daily use, 1,000-2,000 IU is standard, and you should check your blood levels before going higher.

Beetroot juice is rich in nitrates that the body converts to nitric oxide, similar to the arginine-citrulline pathway. The 2019 watermelon juice study is the closest analog here, showing a blood pressure benefit in women [1]. Beetroot juice can lower blood pressure, which is good if yours is high, but could cause dizziness if yours is already low.

My call: this stack is safe for most people at standard doses, but the evidence does not support expecting dramatic benefits from the amino acids and beetroot juice. The real value is likely in the magnesium and vitamin D3 combination, which has a plausible mechanism and some supportive data. Start with the lowest effective doses, monitor your blood pressure, and stop if you feel dizzy or develop digestive upset. Confidence: moderate for safety, low for efficacy of the full stack.