Abstracted by Tatjana Djakovic, MS, from “Vitamin D Supplement Doses and Serum 25-Hydroxyvitamin D in the Range Associated with Cancer Prevention” in the January 19, 2011 Anticancer Research. Vitamin D keeps bones strong, but it also has other health benefits, such as protection from osteoporosis, high blood pressure, cancer, and several autoimmune diseases. Posted June 26, 2012. r/ar
Vitamin D is also known as the “sunshine vitamin”, since the sun plays a role in the activation of this all important molecule in our body. Most people are aware that vitamin D keeps bones strong, but it also has other health benefits, such as protection from osteoporosis, high blood pressure, cancer, and several autoimmune diseases. (1) Vitamin D has had a sustained popularity in the general population in past few years; however, there has not been much information on how consumers use this product. Therefore, a nonprofit community service organization, GrassrootsHealth (GRH,) has assembled a database with information on supplemental vitamin D intake, which has been shown to act as a preventive agent in diseases such as cancer.
Even though experts agree on the health benefits of vitamin D intake, the levels of this molecule in our body needed to achieve those benefits have not reached the same consensus among the experts. The Institute of Medicine (IOM) set a new recommended daily allowance in 2010 based on age, as follows:
- For those 1-70 years of age, 600 IU daily
- For those 71 years and older, 800 IU daily. (3)
The way the levels of stored form of vitamin D are detected in the body is through a blood test that known as 25-hydroxyvitamin D, or 25(OH)D, test. The IOM recommends that serum 25(OH)D levels of 20ng/ml is adequate. (4) However, previous studies have indicated that taking vitamin D in the range from 1,100 to 4000 IU/d and a serum 25 hydroxyvitamin D concentration [25(OH)D] from 60-80 ng/ml are needed to reduce cancer risk. (5,6)
In this first study that analyzes voluntary vitamin D supplementation as practiced in the community, the levels were investigated to determine the amount to take without causing toxicity. The study consisted of 3,667 people with a mean age of 51.3 +/- 13.4 years, in which the participants self-reported their vitamin D intake.
An interesting aspect of the study is that it included individuals of both genders and a wide range of ages and levels of health status. The participants received a blood test and an on-line questionnaire to be completed each six months for a period of five years. The majority of the participants were non-Hispanic whites with intakes of 5000 IU daily or lower. About one-fourth of the participants reported no supplemental vitamin D intake, while 47% reported intakes up to 2,000 ID daily and 1.8% reported intakes above 10,000 IU daily. Importantly, very few individuals had serum 25(OH)D levels above the 200 ng/ml which is the lower boundary for potential toxicity. (2)
It was determined that the supplemental dose ensuring that 97.5% of the participants in the study achieved a serum 25 (OH)D level of at least 40ng/ml was 9,600 IU daily. The African American group had a serum 25 hydroxyvitamin D level of 18.0 (+/- 9.5) ng/ml which is significantly lower than whites, while the eastern Asiatics has a serum level of 26.6 (+/- 23.7) ng/ml. These differences are consistent with the amount of melanin or skin pigment, since melanin is believed to interfere with vitamin D synthesis. (2)
Furthermore, It was determined that the levels of vitamin D in the body that were synthesized using the sunlight solely was 3,300 IU/day or about 32 ng/ml, which is not sufficient to protect against cancer. The toxicity of vitamin D should not pose a concern, because it was found that there is a very slow rise in serum 25(OH)D concentration with each 1,000 IU increment, which confirms the general safety of even high doses. In fact, universal intake of up to 40,000 IU vitamin D per day is unlikely to result in vitamin D toxicity. (2) Therefore, the supplemental intake of the “sunshine vitamin” seems a safe and protective agent against cancer and other diseases.
- Vitamin D http://www.mayoclinic.com/health/vitamin-d/NS_patient-vitamind
- Baggerally L., French C., Garland C., Heany R. Vitamin D Supplement Doses and Serum 25-Hydroxyvitamin D in the Range Associated with Cancer Prevention. Anticancer Research 2011, 31: 2271-2283.
- Vitamin D Dosing http://www.mayoclinic.com/health/vitamin-d/NS_patient-vitamind/DSECTION=dosing
- Vitmain D Testing.http://www.vitamindcouncil.org/about-vitamin-d/vitamin-d-deficiency/am-i-vitamin-d-deficient/
- Garland CF, Gorham ED, Mohr SB, Garland FC: Vitamin D for Cancer Prevention: Global Perspective. Annals of Epiemiology. 2009: 468-483.
- Garland CF, Gorham ED, Mohr SB, Grant WB, Giovannucci EL, Lipkin M, Newmark H, Holick MF, and Garland FC: Vitamin D and Prevention of Breast cancer: Pooled Analyisis. J Steriod Biochem Molec Biol 2007, 103: 708-711.