21st Century Calcium Citrate +D3 Maximum
Brand: 21st Century · Form: TABLET [E0155]
Our assessment
The evidence shows that calcium is essential for your bone health, but the combination of calcium with vitamin D3 in this supplement is standard and well-supported. Based on the data provided, the primary ingredient—calcium—plays a critical role in bone mineralization and neuromuscular function [NIH ODS].
How it works
Think of calcium as a building block for your skeleton. It supports bone density and mineral deposition, and also helps your muscles relax and your nerves send signals properly [NIH ODS]. The vitamin D3 in this formula helps your body absorb that calcium more effectively.
Safety profile
Data not available for this specific product's side effects. However, FDA has received a total of 592,059 adverse event reports across all supplement categories, but specific report counts for this product are not provided [FDA data]. Regarding calcium generally, high intakes may increase the risk of heart disease and prostate cancer, and can cause constipation, nausea, and abnormal heart rhythms at very high levels [NIH ODS].
Our recommendation
Start by assessing your total calcium intake from food and other supplements. Be aware that calcium can reduce the absorption of medications like bisphosphonates, tetracycline antibiotics, and levothyroxine—take this supplement at least two hours apart from those [NIH ODS]. Consult your doctor before starting, especially if you have kidney issues or a history of heart disease.
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | 21st Century |
|---|---|
| Serving Size | |
| Contents | 400.0 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