NOW Calcium Citrate
Brand: NOW · Form: TABLET [E0155] On Market
Our assessment
Our assessment is that calcium is a critical mineral for bone health, but you need to be precise with your dosage and aware of potential risks. The data confirms that calcium supports bone mineralization and nerve signaling [NIH ODS]. However, high intakes may increase the risk of heart disease and prostate cancer [NIH ODS]. For most adults, the goal is to meet, not exceed, the recommended daily intake through a combination of diet and supplements.
How it works
Think of calcium as the building block for your skeleton. It works through bone mineralization, depositing into your bone matrix to maintain density and strength [NIH ODS]. It also plays a key role in neuromuscular relaxation, helping your muscles relax after contraction and supporting proper nerve signaling [NIH ODS]. You need adequate vitamin D to absorb calcium effectively.
Safety profile
FDA received 592,059 adverse event reports for this product category [FDA data]. Safety concerns include that high levels of calcium in the blood and urine can cause poor muscle tone, poor kidney function, low phosphate levels, constipation, nausea, weight loss, extreme tiredness, frequent need to urinate, and abnormal heart rhythms [NIH ODS]. There is also a high risk of death from heart disease with very high levels [NIH ODS]. Calcium can reduce the absorption of several medications, including bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].
Our recommendation
Start by assessing your total daily calcium intake from food and supplements. Do not exceed 2,000 mg total per day from all sources. Take calcium citrate with food for better absorption, and separate it from the medications listed above by at least two hours [NIH ODS]. If you have a history of kidney stones, heart disease, or prostate cancer, consult your doctor before supplementing [NIH ODS]. Data not available on the specific dose per tablet for this product.
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | NOW |
|---|---|
| Serving Size | |
| Contents | 100.0 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