Featured Nutrients

Vitamin A


SuperNutrition Multi-vitamins Now Have More vitamin A!
In 2002, we lowered the retinol vitamin A in our multi-vitamin formulas to 500 IU. We did this because two studies raised concerns that Daily Value potencies of vitamin A (5,000 IU) might cause bone loss in senior women.1,2 Many companies, including SuperNutrition, chose to lower the vitamin A content of their products, or to switch from true retinol vitamin A to the nonessential antioxidant beta-carotene, until further studies were conducted to clarify the findings.

Research has recently been completed that puts to rest any concerns about vitamin A.3 The 2002 studies were calculations derived from a questionnaire-based analysis of the participants’ diets, meaning that they depended on the memory and accuracy of the participants in filling out forms that estimated what they ate. The new research was based on much more accurate blood-test measurements of vitamin A. These recent, more rigorous tests confirmed that retinol vitamin A does not pose a risk for bone loss. In fact, higher, more optimal vitamin A intake increased bone density and reduced bone fractures in senior women.

Beta-carotene Cannot Substitute for True Vitamin A
A "vitamin" is defined as a nutrient essential for life.  Beta-carotene is a beneficial antioxidant, but not an essential vitamin.  Beta-carotene converts to vitamin A in less than half of the population.4,5,6,7 For those who can convert beta-carotene, only about 1/21 of it turns into retinol vitamin A in the body.8,9,10,11 This means that 10,000 IU of beta-carotene turns into about 476 IU of retinol. Thus, beta-carotene cannot be substitute for real retinol vitamin A.8,9,10,11

Vitamin A Is Required For Healthy Pregnancy
The World Health Organization recommends that all pregnant women take retinol vitamin A. They also say that 10,000 IU per day is safe.12 Optimal vitamin A reduces premature delivery by 74%,13 and is required for the health of the baby’s lungs, eyes, immune system, bone and overall growth

Our New Vitamin Doses
Because vitamin A is an essential nutrient which as been demonstrated to be safe and beneficial for men, women, pregnant women, and children, we have raised our vitamin A to recognized, optimal levels.  Our Simply One formulas (not including the newer 50+ multi-vitamins) now have 3,000 IU retinol vitamin A. The Simply One 50+, the advanced blends, and the anti-aging formulas now have 5,000 IU retinol vitamin A, the US government-established Daily Value.

Please feel free to contact us with any further questions.

More Information on Vitamin A

Why Take vitamin A? - (a brief scientific review)
SuperNutrition Review #6 - vitamin A - (a more in-depth review)


  • Promislow JE, and associates. Retinol intake and bone mineral density in the elderly: The Rancho Bernardo Study. Journal of Bone and Mineral Research 2002;17(8):1349-1358.
  • Feskanich D, and associates. Vitamin A intake and hip fractures among postmenopausal women. Journal of the American Medical Association (United States), Jan 2, 2002, 287(1):47-54.
  • Barker ME, and associates. Serum retinoids and beta-carotene as predictors of hip and other fractures in elderly women. Journal of Bone and Mineral research 2005; 20(6):913-920.
  • Lin Y, and associates. Variability of the conversion of beta-carotene to vitamin A in women measured by using a double-tracer study design. American Journal of Clinical Nutrition 2000 Jun;71(6):1545-54.

  • Hickenbottom SJ, and associates. Variability in conversion of beta-carotene to vitamin A in men as measured by using a double-tracer study design. American Journal of Clinical Nutrition 2002 May:75(5): 900-907.
    http://www.ajcn.org/cgi/content/abstract/75/5/900

  • Nierenberg DW, and associates. Effects of 4 y of oral supplementation with beta-carotene on serum concentrations of retinol, tocopherol, and five carotenoids. American Journal of Clinical Nutrition 1997 Aug;66(2):315-319.

  • Aktkuna D, and associates. Beta-carotene, vitamin A and carrier proteins in thyroid processes. Acta Medica Austriaca 1993;20(1-2):17-20.

  • Solomons NW. Plant sources of proVitamin A and human nutriture: How much is still too little? Nutrition Reviews 1999 Nov;57(11):350-361.
  • Tang G, and associates. Vitamin A equivalence of beta-carotene in a woman as determined by a stable isotope reference method.  European Journal of Nutrition 2002 Feb;39(1):7-11.
  • Brubacher GB, and associates. The vitamin A activity of beta-carotene. International Journal of Vitamin and Nutrition Research 1985;55(1):5-15.
  • Hickenbottom SJ. Dual isotope test for assessing beta-carotene cleavage to vitamin A in humans. European Journal of Nutrition 2002
  • Safe vitamin A dosage during pregnancy and lactation. World Health Organization 1998 WHO/Nut/98.4
  • Radhika MS, and associates. Effects of Vitamin A deficiency during pregnancy on maternal and child health. British Journal of Gynecology 2002 Jun;109(6):689-93.

Calcium

More Fun Facts About Calcium:

  • Calcium is an essential mineral that plays a significant role in almost all of our bodily functions.
  • Calcium supports the development and health of our teeth and bones, ultimately protecting the body against debilitating bone loss.
  • 1000mg of calcium has been shown to increase bone density in postmenopausal women by 3% in a two year study.
  • 1200mg of calcium has been shown to increase baby's total mineral content in pregnant women by up to 15%.
  • Calcium carbonate and calcium citrate are commonly used in supplements, and have been found in independent studies to absorb equally when taken with food.1,2,3
  • Calcium is the 5th most abundant mineral in the earth's crust, and the 7th most common mineral in the ocean.
  • Animals can detect calcium in foods, which is a reason that horses are so attracted to salt licks.
  • Calcium was first isolated in 1808 in England by Sir Humphry Davy.
  • Bones and teeth are 50% mineral, 50% protein. Of that mineral content, 64% is calcium.
  • Click here to see our Calcium Blend.

  • Heaney RP, et al., Absorption of calcium as the carbonate and citrate salts, with some observations on method. Osteoporos Int, 9(1):19-23 1999.

  • Harvey JA, et al. Superior calcium absorption from calcium citrate than calcium carbonate using external forearm counting. J Am Coll Nutr (1990) Dec;9(6):583-587.

  • Recker RR. Calcium absorption and achlorhydria. N Engl J Med, 313(2):70-3 1985 Jul 11.

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