Strong consensus that magnesium supplementation improves sleep and energy; glycinate form praised for bioavailability and life-changing effects.
NOW Foods Calcium & Magnesium combines two foundational minerals in a single formula to support bone density, muscle function, and nervous system health. Each serving delivers calcium alongside magnesium in a balanced ratio, formulated for adults looking to maintain adequate intake of both nutrients through daily supplementation.
Why It's Worth Considering: NOW Foods pairs these minerals together because magnesium plays a direct role in calcium metabolism and utilization, making the combination more practical than taking each separately.
| Feature | Glycinate | Citrate | Oxide | L-Threonate | Taurate |
|---|---|---|---|---|---|
| Bioavailability | High (chelated) | Moderate-High | Low (4-5%) | Moderate | Moderate-High |
| Best For | Sleep, anxiety, cramps | Constipation, general | Budget (low absorption) | Cognitive function | Heart health |
| GI Tolerance | Excellent | Moderate | Poor (laxative) | Good | Good |
| Laxative Effect | None | Mild–Moderate | Strong | None | None |
| Evidence | Strong | Strong | Weak | Emerging | Moderate |
Magnesium glycinate (bisglycinate chelate) is widely considered the best form for sleep, anxiety, and muscle cramps due to high bioavailability and zero laxative effect. Citrate is better for constipation. Threonate may be superior for cognitive function as it crosses the blood-brain barrier. Oxide has only 4-5% absorption and is primarily a laxative.
No. Unlike magnesium citrate and oxide which draw water into the intestines (osmotic laxative effect), glycinate is chelated and absorbed through a different pathway that does not affect GI motility. It is the most GI-friendly magnesium form available.
Take 1-2 hours before bed for sleep benefits. The glycine component promotes relaxation via GABA receptor activity. For general supplementation, any time works — glycinate does not require food for absorption.
Standard blood tests (serum magnesium) are unreliable — only 1% of body magnesium is in the blood. Signs include muscle cramps, poor sleep, anxiety, eye twitches, chocolate cravings, and headaches. Since 80%+ of adults are suboptimal, supplementation is generally recommended.
Yes, but separate from zinc, calcium, and iron by 2+ hours (they compete for absorption). Magnesium pairs well with Vitamin D3, K2, and B6 taken together.
The RDA is 310-420mg/day for adults. Most functional medicine practitioners recommend 400-600mg for therapeutic benefit. Start with the product's recommended dose and adjust based on response.
† These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
