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Better Bones Blog
Dr. Susan E. Brown

New research shows how lack of nutrients affects bone

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There’s a wide range of nutrients that affect bone.  And now I’m happy to say there’s a wide range of research as well that tells us how important these nutrients are for bone strength.

Here are some highlights from the findings from the 9th International Symposium on Nutritional Aspects of Osteoporosis which I attended:

  • Multi-nutrient inadequacy and osteoporosis: A Brazilian study looking at individuals with and without osteoporosis found that those with osteoporosis had significantly lower intake of many nutrients including protein, calcium, potassium, vitamin K, magnesium, zinc and vitamin D. (Põlluste et al. 2015)
  • Vitamin A and beta-carotene: Higher blood levels of both vitamin A and beta-carotene were associated with higher bone mineral density amongst Chinese adults. (Zhang et al. 2015)
  • Magnesium in bone density: Among Brazilian women bone mineral density was found to be greater in women who with the highest magnesium intake, as compared to those with an official deemed “adequate’ intake. (Peters et al. 2015)
  • Vitamin E and bone density: A large Chinese study found that higher vitamin E intake was positively associated with higher bone mineral density and a lowered risk of osteoporosis among older women. (Chen et al. 2015)
  • Vitamins K, D and fracture risk: A very large Norwegian study found that participants with both low circulating vitamin K1 and vitamin D had a 50 percent increased risk of hip fracture as compared to those with higher levels of these nutrients. (Finnes et al. 2015)

For three decades, we’ve championed adequate intake of all key bone building nutrients. So you can imagine our delight to see medical researchers are studying how intake of key bone nutrients beyond just calcium and vitamin D benefit skeletal health.

 

References:

Chen, Y. M., W. Q. Shi, J. Liu, Y. Cao, Y. Y. Zhu, and K. Guan. 2015.  Association of dietary and serum vitamin E with bone mineral density in middle-aged and elderly Chinese: A cross-sectional study. Presentation at 9th International Symposium on Nutritional Aspects of Osteoporosis. 17-20 June 2015, Montreal, Canada.

Finnes, T. E., C. M. Lofthus, A. J. Søgaard, G. S. Tell, E. M. Apalset, C. Gjesdal, G. Grimnes, B. Schei, R. Blomhoff, S. O. Samuelsen, K. Holvik, and H. E.

Meyer.2015. Increased risk of hip fracture in older Norwegians low in both circulating vitamin K1 and 25-hydroxyvitamin D: A NOREPOS study. Presentation at 9th International Symposium on Nutritional Aspects of Osteoporosis. 17-20 June 2015, Montreal, Canada.

Peters, B. S. E., M. B. R. Camargo, M. Lazaretti-Castro, N. A. G. de França, and L. A. Martini. 2015. Relationship between magnesium intake and bone mass density in Brazilian postmenopausal women. Presentation at 9th International Symposium on Nutritional Aspects of Osteoporosis. 17-20 June 2015, Montreal, Canada.

Põlluste, K., M. Kull, R. Müller, A. Aart, R. Kallikorm, and M. Lember. 2015. Nutritional deficiencies and bone mineral density in a cohort of patients referred to osteoporosis clinic. Presentation at 9th International Symposium on Nutritional Aspects of Osteoporosis. 17-20 June 2015, Montreal, Canada.

Zhang, C. X., G. D. Chen, Y. Cao, Y. Y. Zhu, and Y. M. Chen. 2015. Association of dietary consumption and serum levels of vitamin A and β-carotene with bone mineral density in Chinese adults. Presentation at 9th International Symposium on Nutritional Aspects of Osteoporosis. 17-20 June 2015, Montreal, Canada.

Better Bones Blog
Dr. Susan E. Brown

Key vitamins for bone health — vitamin A

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Vitamin A plays an essential role in the development of osteoblasts, the bone-building cells that lay down new bone. A deficiency in vitamin A also limits calcium absorption and metabolism, which can result in poor bone growth. Overall, low vitamin A levels are associated with osteoporosis and increased risk of fracture.

On the other hand, there is some controversy as to whether high vitamin A intakes are actually helpful, or more of a hindrance to bone health. Some studies suggest high vitamin A can be bone-damaging, but this relates only to the active forms of vitamin A, or retinoids. The jury is still out on how — or even if — excess vitamin A intake actually increases risk of osteoporosis and bone fracture. But in the meantime, we recommend limiting intake of supplemental vitamin A — that is, preformed vitamin A, or retinoid forms — to 5000 IU per day. This is still well below the known tolerable upper limit (UL) of preformed vitamin A — around 10,000 IU per day.

What do we mean by “preformed” vitamin A? There are many forms of vitamin A, with retinoids and carotenoids being the two main categories.

    • Retinoids — natural, fat-soluble forms of vitamin A that are available for immediate use in the body. Derived from animal sources, retinoids are a smaller class than the carotenoids, and include retinol, retinal, and retinoic acid, among others.
  • Subgroup: Retinol — also referred to as “preformed vitamin A,” retinol is regarded as the main active form for vitamin A in the body. It is found naturally in some animal tissues, such as liver, which makes liver a good dietary source of this vitamin.
    • Carotenoids — a large class of natural, fat-soluble pigments found principally in deeply-colored plant foods. Carotenoids, sometimes referred to as provitamins, are dietary precursors to the active forms of vitamin A in the body. More than 600 carotenoids have been identified to date.
  • Subgroup: Beta-carotene — the most well-known plant precursor source of active vitamin A. Our bodies can convert beta-carotene into active vitamin A when needed, storing or eliminating any extra.

A full description of the hundreds of forms and functions of vitamin A is beyond the scope of this article, so here are a few key points to remember:

  • Most of the vitamin A in our diets comes from plants in the form of beta-carotene, which, again, is a precursor that is safely stored in our body fat and liver, where it gets converted into active vitamin A forms as needed.
  • Retinol, the primary form of active vitamin A, can be toxic if consumed at very high levels.
  • Thanks to an inbuilt mechanism that shuts off our body’s conversion of beta-carotene into retinol when levels are adequate, high intake of beta-carotene is generally not of concern.
  • Some recent research has, however, linked high-dose beta-carotene supplements to increased risk of lung cancer among smokers — the opposite seems to be the case among nonsmokers!
  • Though there may be different thoughts on what constitutes “high-dose beta-carotene,” amounts over 25,000 IU are typically considered to be in the higher range.
  • Science is always evolving, but Better Bones products have been well-formulated and contain useful, nontoxic amounts of both forms as part of supplement regimen.

Today, for the approximately 44% of the US population that under-consume vitamin A in their food, supplementing with both the above-described forms of vitamin A is a wise move for bone health.

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