Natural Factors Whole Earth & Sea Bone Structure Multivitamin & Mineral

Our assessment

The evidence shows that this product provides calcium, a mineral essential for bone health. The data confirms that calcium supports bone density and mineral deposition, and plays a role in muscle relaxation and nerve signaling [NIH ODS]. For a general audience seeking to support bone structure, this supplement offers a targeted approach, but you should be aware of the specific intake levels and potential risks.

How it works

Think of calcium as a structural building block for your bones. It works through bone mineralization, directly supporting the density and strength of your skeletal framework [NIH ODS]. Additionally, calcium aids in neuromuscular relaxation, helping your muscles relax properly and supporting healthy nerve signaling throughout your body [NIH ODS].

Safety profile

The FDA has received a total of 592,059 adverse event reports across all dietary supplements, though data specific to this product is not available. For calcium specifically, some research suggests that high intakes might increase the risk of heart disease and prostate cancer [NIH ODS]. Very high levels of calcium in the blood 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]. 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 the label for the exact calcium dosage per serving. If you are taking any medications, especially those listed above, separate your supplement intake by at least 2 hours to avoid absorption issues [NIH ODS]. Do not exceed the recommended daily intake without consulting your healthcare provider, as high calcium levels carry significant risks [NIH ODS]. This supplement is best used as part of a balanced approach to bone health, not as a standalone solution.

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