NOW Magnesium & Calcium
Brand: NOW · Form: TABLET [E0155] On Market
Our assessment
The evidence shows that this supplement provides two essential minerals with clear roles in bone and nerve health. Calcium is critical for bone mineralization and neuromuscular relaxation [NIH ODS]. However, you should be aware that high calcium intakes may pose risks, and we recommend careful dosing based on your total dietary intake [NIH ODS].
How it works
Think of calcium as a structural builder for your skeleton — it supports bone density and mineral deposition [NIH ODS]. It also acts as a nerve signal regulator, helping your muscles relax and your nerves transmit signals properly [NIH ODS]. The combination with magnesium in this product may support these processes, though specific data for this exact combination is not available.
Safety profile
FDA has received a total of 592,059 adverse event reports for products in this category [FDA data]. For calcium specifically, high intakes might increase the risk of heart disease and prostate cancer [NIH ODS]. Very high levels in the blood and urine can cause poor muscle tone, poor kidney function, low phosphate levels, constipation, nausea, weight loss, extreme tiredness, frequent urination, abnormal heart rhythms, and a high risk of death from heart disease [NIH ODS]. Calcium can also reduce the absorption of several medications, including bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].
Our recommendation
Start by reviewing your daily calcium intake from food and other supplements. If you take this product, take it separately from any medications listed above by at least 2 hours [NIH ODS]. Do not exceed the recommended dose on the label without consulting your healthcare provider. For most adults, total calcium intake from all sources should be carefully monitored to avoid the risks associated with high levels [NIH ODS].
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | NOW |
|---|---|
| Serving Size | |
| Contents | 250.0 Tablet(s) |
| Market Status | On 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