OS-Cal® Ultra Calcium Compared to AlgaeCal®

Below is a comparison of Oscal calcium supplement to AlgaeCal Plus. You will notice the formulas might appear to be similar, but when you dig deeper there are many differences between the two bone health products.

Differences Between OS-Cal Ultra and AlgaeCal Plus

      1. Calcium – AlgaeCal is organic plant source calcium from marine algae – Oscal calcium is inorganic laboratory made calcium carbonate. OS-Cal Ultra may have 1200 mg of calcium in a daily serving but as the average individual gets 600 mg of calcium from their diet,1-2 it is unnecessary to supplement in such large amounts.
      2. Vitamin K2 – The AlgaeCal formula contains vitamin K2. New research shows that vitamin K2 is proven to increase bone mineral density – learn more about Vitamin K2
      3. Magnesium – New studies show that supplementing magnesium with calcium increases bone mineral density.3 The AlgaeCal formula contains 350 mg of magnesium where OS-Cal only contains 40 mg in the recommended daily serving. – more about the Benefits of Magnesium
      4. Trace Minerals – AlgaeCal naturally contains 73 trace minerals from algae, the Oscal formula has added zinc, copper and manganese to their formula synthetically.
      5. Tablets – OS-Cal Ultra comes in tablet form rather than veggie capsules, and tablets are a less bio-available delivery system.4 The tableting requires many additives of questionable value such as “cellulose, crospovidone, FD and C blue No. 2, red No. 40, and yellow No. 6, Magnesium Stearate, polysorbate, povidone, sodium croscarmellose, starch, sucrose, titanium dioxide, triacetin”.
OS-Cal Ultra Recommended daily serving: 2 Tablets

Amount Per Serving
Vitamin D3 (Cholecalciferol)
400 IU
Vitamin C
60 mg
Vitamin E
5 IU
Calcium Carbonate
1200 mg
40 mg
15 mg
2 mg
2 mg
250 mcg


AlgaeCal Plus Supplement Facts Serving Size: 4 Capsules

Amount Per Serving
Vitamin D3 (Cholecalciferol)
1600 IU
Vitamin K2 (as MK-7)
100 mcg
Calcium (from Algas Calcareas)
720 mg
Magnesium (from Algas Calcareas + magnesium carbonate)
350 mg
Trace Minerals (from Algas Calcareas)
1464 mg
Boron (Glycinate)
3 mg
Vitamin C (calcium ascorbate)
50 mg

More Reasons to Choose AlgaeCal Plus over OS-Cal Calcium

          • AlgaeCal offers an iron clad guarantee! Guaranteed bone growth within 180 days or your money back.

If you are serious about your bone health then you have to consider the facts. OS-Cal calcium does not contain the clinically proven bone building ingredient Vitamin K2 and lacks the adequate amount of Vitamin D. Also, the calcium form does not compare to organic, whole food, plant-source AlgaeCal.

AlgaeCal Plus

AlgaeCal is the world’s only pure plant source of calcium, so it is a particularly body-friendly form of calcium with a 97% calcium absorption” rate. It also naturally includes magnesium and important bone-supporting trace minerals in a form that your body recognizes as food. Vitamin D3 and vitamin K2 have been added at full dosages.Learn more about AlgaeCal Calcium Supplement AlgaeCal Plus Product


1. Bischoff-Ferrari, H.A., et al. 2004. Effect of vitamin D on falls: A meta-analysis. Journal of the American Medical Association 291(April 28):1999-2006

2. Heaney RP, Dowell MS, Hale CA, Bendich A. Calcium absorption varies within the reference range for serum 25-hydroxyvitamin D. J Am Coll Nutr. 2003;22(2):142-146. (PubMed)

3. Holick MF. Vitamin D deficiency: what a pain it is. Mayo Clin Proc. 2003;78(12):1457-1459

4. Heaney RP. Factors influencing the measurement of bioavailability, taking calcium as a model. J Nutr. 2001 Apr;131(4 Suppl):1344S-8S