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Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Increasing incidence of rickets: Is D deficiency the culprit?

Rickets, once a public health problem of urgent importance, has largely fallen off the public’s radar. However, many prominent vitamin D researchers are calling attention to a “resurgence of rickets,” fueled in many cases by low blood levels of vitamin D. The Mayo Clinic wondered just how much rickets has increased in recent years and what is causing it.

Thacher TD, Fischer PR, Tebben PJ, et al. Increasing incidence of nutritional rickets: a population-based study in olmsted county, Minnesota. Mayo Clin Proc. 2013;88(2):176-83.

Nutritional rickets is a disease of improper bone mineralization caused by a deficiency of vitamin D, calcium, or phosphate. Symptoms include bone pain, low blood levels of calcium, and the “bow leg” deformity classically associated with the disease.

Due to increasing concerns that rickets is on the rise, the Mayo Clinic investigated the medical records of all children on file in Olmsted County, Minnesota between 1970 and 2009 to determine how many children were diagnosed with health conditions indicative of nutritional rickets in this time period. Radiographic confirmation was required for a diagnosis of rickets. The children with rickets were then compared with healthy controls to determine risk factors for developing the bone disease.

  • In total, 768 medical records of children with diagnostic codes indicating cases of rickets were identified.
  • 23 of these cases of rickets were confirmed with radiography
  • 17 of the radiography-confirmed cases were nutritional rickets

Children whose rickets appeared to be caused by genetic or in-born errors of metabolism (non-nutritional) were excluded. Two of the seventeen cases occurred in new immigrants from the Middle East and were thus considered “imported.” Four occurred in the children of recent Somali immigrants. The median 25(OH)D level of children diagnosed with rickets was 13 ng/mL.

Compared to healthy controls, children diagnosed with rickets were more likely to be black, breast-fed, and of lower weight and height. The researchers noted that poor feeding, a low intake of milk and meat products, low amounts of sun exposure, and prematurity were noted in the medical records of the children with rickets as potential contributors to their development of the disease.

The researchers found that while the incidence of rickets remained relatively constant between 1970 and 2000, it markedly increased after 2000. While the Mayo Clinic increased its testing of vitamin D levels ten-fold after the year 2002, they note that the majority of the children with rickets first came to the attention of medical professionals based on clinical and not biochemical abnormalities. In other words, disease symptoms and not a vitamin D test were what most frequently alerted the diagnosing doctor to the presence of a problem.

Potential reasons for the increase of rickets were offered:

  • An increase in the number of dark-skinned immigrants in Olmsted County between 1970 and 2009
  • A decline in the average blood levels of vitamin D in the US between 1994 and 2004

Recent research in the United Kingdom and Australia indicates that the increase of rickets in recent years parallels the increase of black immigrants to these countries. Darker-skinned individuals are more likely to be vitamin D deficient, and this could be causing an increase of rickets in their children. This same situation could very likely be occurring in Olmsted County, too.

Between 1994 and 2004, the number of individuals in the US with a 25(OH)D level below 30 ng/mL doubled. The increased use of sunscreen and increased avoidance of sun are cited as reasons for this trend.

Limitations of the study include a lack of radiographs for all children with diagnostic codes indicative of rickets. The authors note that had radiographs been performed on all of these children, the number of children with the diagnosis of nutritional rickets would likely be increased. Also, the study was underpowered to detect a seasonal variation in rickets diagnoses.

The researchers urge that pregnant women be tested for vitamin D deficiency and supplemented accordingly and that all breast-fed children receive vitamin D supplements. Rickets should be suspected in children that fail to grow properly, especially those that are breast-fed and of black race.

It is important to remember that while overt vitamin D deficiency can cause rickets, the low vitamin D levels present in many children are likely contributing to subclinical bone disease that manifests in unsuspected ways. Dr. Cannell has reported extensively on this phenomena.

It is critical that pregnant women not only optimize their vitamin D levels during pregnancy, but that they take steps to ensure their infants’ adequate vitamin D status after delivery. Vitamin D is not reliably transferred in the breast milk until the mother’s 25(OH)D level is 45-50 ng/mL or higher as has been previously reported.

If the breastfeeding mother’s level is not at least 45-50 ng/mL, the baby should receive oral vitamin D supplementation. Bone disease and many other tragic conditions resulting from vitamin D deficiency are largely avoidable in pregnant women and their infants after delivery when natural levels of vitamin D are maintained.

  About: Rebecca Oshiro

Rebecca has a master of science degree in nutrition from Bastyr University where she conducted a university-funded study on vitamin D and athletic performance. She has a certificate in applied behavior analysis from the Florida Institute of Technology, and her passion is using behavioral technologies to assist others in making meaningful changes in their lives.

4 Responses to Increasing incidence of rickets: Is D deficiency the culprit?

  1. Rita and Misty says:

    This was an excellent posting :) …and truly emphasizes the great need for expectant moms in the African American community to ensure that they have adequate Vitamin D levels… The health of Black children, as well, is in grave danger from Vitamin D deficiency, and both moms and children especially need to be tested and given Vitamin D according to their 25(OH)D results.

    As common with public health issues, women and children are many times the most severely impacted.

    I’ve said it before, and I will say it again:

    Because of our indoor lifestyles, Vitamin D deficiency is at epidemic proportions in the United States…actually worldwide. And it is worse among those with darker skin pigmentation, as melanin factors greatly into Vitamin D production.

    The sunlight needs for people with darker skin pigmentation, living at higher latitudes, are immense and are not being met. A lighter pigmented person standing in full sun can produce a day’s bodily requirement of Vitamin D in about 15 minutes. In stark contrast, a person with darker skin pigmentation, standing in the same spot, will need approximately 6 times more sun exposure to produce the same amount of vitamin D. The following link will provide you with a thorough explanation:

    http://www.vitamindcouncil.org/about-vitamin-d/how-to-get-your-vitamin-d/uvb-exposure-sunlight-and-indoor-tanning/

    According to reports by the United States Center for Disease Control and Prevention, African American suffer greatly from chronic diseases such as cancer, heart disease, fibromyalgia, lupus, and obesity which can be effectively controlled or prevented with vitamin D supplementation.

    Unfortunately, many African Americans do not know about the health enhancing properties of vitamin D so their health continues to deteriorate.

    Despite the alarming health situation for Blacks, conventional medical practitioners do not seem to be informing Black people that they may need to take at least 5,000 IU of vitamin D3, in supplement form, every day; and that Black children should also be given adequate amounts of vitamin D3 on a daily basis, because food and drinks do not supply adequate amounts of vitamin D. Instead, all of us continue to be overloaded with prescription medications that treat the symptoms of illnesses while the causative factors are left unaddressed.

  2. Rebecca Oshiro says:

    Rita, thank you for those sobering comments. While there are obvious socioeconomic disparities that explain the different health outcomes between blacks and whites, the vitamin D deficiency piece of the puzzle has been largely ignored to the great peril of those with darker skin.

  3. Rita and Misty says:

    This information re: wheat/D/rickets just blew me away:

    “As early as 1949, the researcher Dr. Edward Mellanby, the discoverer of vitamin D, demonstrated the demineralizing effects of phytic acid. By studying how grains with and without phytic acid affected dogs, Mellanby discovered that consumption of high-phytate cereal grain interferes with bone growth and interrupts vitamin D metabolism. High levels of phytic acid in the context of a diet low in calcium and vitamin D resulted in rickets and a severe lack of bone formation.”

    Learn more: http://www.naturalnews.com/030512_whole_grains_phytic_acid.html#ixzz2fvgkxBQQ

  4. Rita and Misty says:

    This is also very interesting to me, Please note that I do not advocate Cod Liver Oil–as I do think it contains way too much A, and too much A hinders the body’s proper utilization of D.

    “Rickets and, in adolescents and adults, osteomalacia are conditions caused by vitamin D deficiency: without vitamin D (actually a steroid hormone rather than a vitamin in the modern sense), the body cannot absorb calcium or phosphorus, and therefore cannot properly build bones. In the nineteenth and early twentieth centuries, rickets flourished in Northern Europe and North America, particularly among the urban (often immigrant) poor. Although the mechanism by which vitamin D is produced and functions in the body remained only partially understood until the 1980s and 1990s, researchers knew by 1918 that the vitamin D deficiency diseases could be cured by feeding cod-liver oil and, by the early 1920s, that they could also be treated by direct UV radiation and the radiation of certain foodstuffs. Vitamin D became known as the “sunshine vitamin.”22 The relative importance of environmental and nutritional factors in the generation of rickets, however, remained hotly debated, illustrating continued polarities between clinical and laboratory models of medical research.23”

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2630160/