21st Century Calcium 500 + D3 Plus Extra D3
Brand: 21st Century · Form: TABLET [E0155] On Market
Our assessment
The evidence shows that this product provides 500 mg of calcium and an undisclosed amount of vitamin D3. Calcium is essential for bone health, but the data highlights important safety considerations you need to know before taking this supplement [NIH ODS].
How it works
Think of calcium as a master mineral for your body. It supports bone mineralization and density, and it plays a key role in neuromuscular relaxation and nerve signaling [NIH ODS]. The product name mentions "Extra D3," which helps your body absorb that calcium more effectively.
Safety profile
The FDA has received 592,059 total adverse event reports for all products. For calcium specifically, high intakes may increase the risk of heart disease and prostate cancer. High blood and urine levels of calcium 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] [FDA data]. Calcium can also reduce the absorption of medications including bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].
Our recommendation
Start by evaluating your total daily calcium intake from food and other supplements. If you take this product, be aware of the potential for side effects and drug interactions. Data not available for the specific vitamin D3 dosage in this product, so consult your healthcare provider for personalized advice [NIH ODS].
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | 21st Century |
|---|---|
| Serving Size | |
| Contents | 60.0 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