NOW Calcium Citrate
Brand: NOW · Form: TABLET [E0155]
Our assessment
The evidence shows that calcium is a foundational mineral for your bone health and nerve function. Our assessment: when used correctly, calcium citrate can be a valuable supplement, but you need to be careful with dosing and timing. The data confirms that calcium supports bone density and muscle relaxation, but it’s not a simple “more is better” nutrient [NIH ODS].
How it works
Think of calcium as a structural builder and a signal messenger. It works by depositing into your bones to maintain density and strength — a process called bone mineralization. At the same time, calcium helps your muscles relax after contracting and supports your nerves in sending signals properly [NIH ODS]. This dual role is why getting the right amount matters for your whole body.
Safety profile
Safety data shows you must be cautious with calcium. High calcium intake might increase the risk of heart disease and prostate cancer [NIH ODS]. High levels in your blood and urine can cause 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]. The FDA has received a total of 592,059 adverse event reports across all products in this category [FDA data]. Additionally, calcium can reduce the absorption of medications like bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].
Our recommendation
Our recommendation: do not exceed your daily needs without a doctor’s guidance. If you take calcium citrate, take it separately from your thyroid medication or antibiotics by at least 2 hours to avoid absorption issues [NIH ODS]. Start with a moderate dose and monitor for constipation or nausea. For specific dosing, data on your exact product’s label is not available here, so check the bottle carefully.
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | NOW |
|---|---|
| Serving Size | |
| Contents | 100.0 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