NOW Magnesium & Calcium
Brand: NOW · Form: TABLET [E0155]
Our assessment
The evidence shows that a combination supplement like NOW Magnesium & Calcium can be a convenient way to support bone health, but you need to be careful with dosing. Calcium is critical for bone mineralization, and it also supports neuromuscular relaxation and nerve signaling [NIH ODS]. However, getting the right balance is key, as taking too much calcium carries real risks.
How it works
Think of calcium as the structural building block for your bones. It works by depositing into your bone matrix to maintain density and strength [NIH ODS]. At the same time, it acts as a cellular messenger, helping your muscles relax properly after they contract and ensuring your nerves can send signals efficiently [NIH ODS].
Safety profile
Data not available on the specific number of adverse event reports for this product alone. However, the FDA has received a total of 592,059 adverse event reports across all supplement categories. For calcium specifically, high intakes might increase the risk of heart disease and prostate cancer [NIH ODS]. Extremely high levels of calcium in your blood and urine can lead to poor muscle tone, poor kidney function, low phosphate levels, constipation, nausea, weight loss, extreme tiredness, frequent need to urinate, abnormal heart rhythms, and a high risk of death from heart disease [NIH ODS].
Our recommendation
Our assessment: This supplement is likely safe for most people when taken as directed, but you must be mindful of your total calcium intake from all sources (food + supplements). Calcium can reduce the absorption of several medications including bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS]. We recommend taking this supplement with food and spacing it at least two hours apart from any of those medications. If you have a history of kidney stones or heart disease, consult your doctor before starting [NIH ODS].
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | NOW |
|---|---|
| Serving Size | |
| Contents | 250.0 Tablet(s) |
| Market Status | Off Market |
How to Read This Label
Supplement labels contain several key sections regulated by the FDA:
- Serving Size — The recommended amount per dose. Always check this — some products require multiple capsules per serving.
- Amount Per Serving — Shows the quantity of each nutrient in the product, typically in IU (International Units), mg (milligrams), or mcg (micrograms).
- % Daily Value (%DV) — Indicates how much a nutrient in a serving contributes to a daily diet. 5% DV or less is low; 20% DV or more is high.
- Other Ingredients — Lists inactive ingredients like fillers, binders, and capsule materials (e.g., gelatin, cellulose, magnesium stearate).
- Suggested Use — The manufacturer's recommended directions for taking the supplement, including timing and dosage.
Source: FDA Dietary Supplement Labeling Guide