Most people do not get enough vitamin D in their diet, reports Harvard School of Public Health. African-Americans and older people tend to have much lower vitamin D levels, along with overweight or obese people. Being “D-ficient” has worried many practitioners over the years, but now, there is a medical divide, as one side argues vitamin D levels do not play as important a role as once thought.
On a global scale, an estimated 1 billion people have inadequate levels of the vitamin in their blood. Even in developed countries, doctors are seeing a resurgence of rickets, which is a bone weakening disease that was once eradicated with vitamin fortification. The low levels of vitamin D are such a concern because of the broader impact of the deficiency on health, Harvard researchers say.
There is a scientific debate over how much vitamin D people actually need every day. In 2010, the Institute of Medicine released a report that recommends tripling the daily vitamin D intake for children and adults. The recommended level changed to 600 IU per day. The upper limit was adjusted from 2,000 IU to 4,000 IU per day. However, the Harvard School of Public Health reports that even at 4,000 IU there is no detrimental harm, and people might actually be able to take more. For bone health and chronic disease prevention, people likely need more than these guidelines suggest even.
Not everyone believes this vitamin has as many health benefits as proponents claim. A study by Dr. Bolland PhD, Andrew Grey MD et al. involved a trial sequential meta-analysis and found that vitamin D levels, or as previously mentioned, being “D-ficient,” does not necessarily increase one’s risk of disease. When the vitamin is taken with or without calcium there is no reduced bone and non-bone related outcomes (breaking the 15 percent threshold set by the researchers).
Bollan and others reviewed studies consisting of supplementation for cancer, stroke or cerebrovascular disease, ischaemic heart disease or myocardial infarction, bone fracture, and mortality. This study was published in The Lancet Diabetes & Endocrinology.
The Mayo Clinic reports that low vitamin D can cause bones to become thin, brittle, or misshapen. The interrelatedness of vitamin D and insulin resistance, along with high blood pressure, immune function, and other diseases like cancer, is currently under investigation. Mayo Clinic also reports that 600 IU of this vitamin a day is currently considered sufficient for adults, but those who are older than age 70 should be taking 800 IU a day.
In contrast, WebMD says Vitamin D deficiency can increase the risk of death from cardiovascular disease; can cause cognitive impairment in older adults; can cause severe asthma in children, and can even lead to cancer. Symptoms include bone pain and muscle weakness. WebMD also reports that vitamin D could act as a preventative treatment for various health conditions including diabetes, hypertension, glucose intolerance, and multiple sclerosis.
People are encouraged to supplement for this vitamin, even if it just means consuming food with vitamin D fortification, or by spending more time in the sun. If vitamin D levels remain chronically low, it can be a sign that a person is unable or inefficiently absorbing the vitamin in their intestinal tract, which is a common cause for a “D-ficient” patient. Crohn’s disease, cystic fibrosis, and celiac disease could potentially cause this malabsorption. Another cause could be when kidneys are failing to convert the vitamin to its active form, which is reportedly one of the effects of aging.
By Lindsey Alexander