This article was originally published on June 28, 2019, and has since been updated.
There has been a lot of interest in the media lately about vitamin D. Much of the data has come from the National Health and Nutrition Examination Survey (NHANES). Statistics show that more than 90% of the population in the United States currently live with vitamin D deficiency. These numbers represent nearly double the amount of insufficiency seen just ten years ago. (1)
Vitamin D is a fat-soluble vitamin that is stored in fatty tissues of the body and the liver. What is unique about vitamin D is that our bodies make most of it when exposed to the sun. When UV-B rays make contact with our skin it provides the energy for a substance called 7-dehydrocholesterol to convert to cholecalciferol (vitamin D3).
8 Benefits of Vitamin D
Why do we need vitamin D? This vitamin plays numerous roles throughout the body, including bone and brain health, cell growth, immune function and more.
Bone health-The body needs vitamin D to absorb calcium, which is critical for healthy bones and teeth. Vitamin D is also needed to help the body metabolize phosphorous, another important mineral for bone health. Rickets, a condition characterized by weak, soft bones, is caused by serious D3 deficiency.
Cancer -While research is somewhat limited on how D3 affects cancer. The research does imply that deficiency could be linked to a higher risk of numerous cancers, including breast, colon, kidney, stomach, and ovarian cancers. (2)
Cognitive performance-Deficiency in vitamin D in older adults was associated with decreased levels of cognitive performance, as well as mood changes and physical performance. Researchers found a strong link between dementia, Alzheimer’s, and vitamin D deficiency. (3, 4)
Immune function-Vitamin D is a powerful proponent to increase immunity and protect the body from infection. This study shows the increased risk of respiratory tract infections for those with D deficiency. (5)
Diabetes-A study published in the PLOS One Journal states that a vitamin D deficiency may put people at higher risk for type 2 diabetes. (6)
Heart health-Numerous studies have linked vitamin D deficiency to heart failure and coronary heart disease. Vitamin D is able to block the action of cCFU-Fs (cardiac colony-forming unit fibroblasts), which prevents the buildup of scar tissue and could potentially stop a blockage from developing. (7, 8, 9)
Hair loss/alopecia-Vitamin D promotes hair follicle growth; deficiency can be the origin of some hair loss cases. Vitamin D deficiency is common in people with alopecia, as well as low serum ferritin levels. (10, 11)
Excess belly fat-Higher levels of belly fat are linked with lower vitamin D levels in obese individuals. Checking your vitamin D levels would be important to avoid any potential health problems. (12)
Read: Massive Study Shows Vitamin D Supplements May Help Fend Off Dementia
Vitamin D Deficiency Linked to Belly Fat
Researchers from VU Medical Center and Leiden University Medical Center (in the Netherlands) focused their study on a connection between obesity and low vitamin D levels. The study included thousands of women and men aged 45-65. (13)
The study centered on total fat, abdominal subcutaneous adipose tissue, hepatic (liver) fat and visceral adipose tissue. Adjustments were made for various factors such as smoking, alcohol consumption, chronic disease, and physical activity.
It was discovered that there was a link between women with abdominal fat and total fat and low vitamin D levels, whereas low vitamin D levels in men were associated with abdominal and liver fat. However, in all instances, the larger the amount of belly fat, the lower the levels of vitamin D were detected.
The results were presented in Barcelona at the European Society of Endocrinology annual meeting, ECE 2018. Dr. Rachida Rafiq shares, “The strong relationship between increasing amounts of abdominal fat and lower levels of vitamin D suggests that individuals with larger waistlines are at a greater risk of developing a deficiency, and should consider having their vitamin D levels checked.” (13)
Dr. Rafiq’s next step is trying to determine why the correlation exists, she also states that “Due to the observational nature of this study, we cannot draw a conclusion on the direction or cause of the association between obesity and vitamin D levels.” (13)
How Much D Do We Need?
There is a lot of debate about how much vitamin D is adequate. Recommended amounts vary based upon gender, age, and overall health. A blood test called 25-hydroxy-vitamin D test can determine your levels of vitamin D and whether or not a deficiency is present.
According to the National Institute of Health recommended amounts in international units are as follows: (14)
- Birth to 12 months: 400 IU
- Children 1-13 years: 600 IU
- Teens 14-18 years: 600 IU
- Adults 19-70 years: 600 IU
- Adults 71 years and older: 800 IU
- Pregnant and breastfeeding women: 600 IU
It’s important to note that RDA (Recommended Daily Amount) is the minimum amount to avoid illness, it is not the optimal amount. Many people believe that D3 amounts should be higher, which is why it is important to have a blood test to determine your vitamin D levels and to determine an adequate dosage for you.
Read: Vitamin D Deficiency Causes Death, New Study Finds
What Vitamin D Blood Tests Reveal
The most accurate blood test to measure vitamin D is the 25-hydroxyvitamin D test or 25(OH)D test. The test will measure the vitamin D level by nanograms per milliliter (ng/mL)
The Institute of Medicine (IOM) proposes that that 20 ng/mL is a suitable amount for bone and overall health in healthy individuals. Yet other groups argue that amounts should be higher. (6)
The Mayo Medical Laboratories Reference Range for Total Serum 25-Hydroxyvitamin D is as follows: (15)
|Severe deficiency||<10 ng/mL|
|Mild to moderate deficiency||10-24 ng/mL|
|Possible toxicity||> 80 ng/mL|
This study was observational, so no clear conclusion can be drawn between obesity and low vitamin D levels. While it has limitations, vitamin D is important for many healthy bodily functions.
This does not mean you can take a supplement and have your body fat disappear. Due to the correlational nature of the study, it could be plausible that being active in the sun (also meaning a higher vitamin D production) could lead to lower body fat percentages. The best way to get adequate vitamin D is through spending time outdoors with safe sun exposure. Add supplements if needed, specifically D3, which is more easily absorbed by the body than D2.
Only take high doses of D under the supervision of your doctor. Taking too high a dose can cause the liver to produce (OH)D, which causes calcium to build up in your bloodstream. Side effects can include nausea, constipation, increased thirst, abdominal pain, and loss of appetite.
Remember these numbers if you get a vitamin D blood test:
- <10-Severly Deficient
- 10-24-Mildy Deficient
- 25-80 –Optimal
- >80 Possible Toxicity
- Adams, J. S., & Hewison, M. (2010, February). Update in vitamin D. Retrieved June 25, 2019, from https://www.ncbi.nlm.nih.gov/pubmed/20133466
- Vuolo, L., Di Somma, C., Faggiano, A., & Colao, A. (2012, April 23). Vitamin D and cancer. Retrieved June 25, 2019, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3355893/
- Wilkins, C. H., Sheline, Y. I., Roe, C. M., Birge, S. J., & Morris, J. C. (2006, December). Vitamin D deficiency is associated with low mood and worse cognitive performance in older adults. Retrieved June 25, 2019, from https://www.ncbi.nlm.nih.gov/pubmed/17138809
- Littlejohns, T. J., Henley, W. E., Lang, I. A., Annweiler, C., Beauchet, O., Chaves, P. H., . . . Llewellyn, D. J. (2014, September 02). Vitamin D and the risk of dementia and Alzheimer disease. Retrieved June 25, 2019, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4153851/
- Ginde, A. A., Mansbach, J. M., & Camargo, C. A. (2009, February 23). Association between serum 25-hydroxyvitamin D level and upper respiratory tract infection in the Third National Health and Nutrition Examination Survey. Retrieved June 25, 2019, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3447082/
- PhD, C. P. (2018, April 23). How vitamin D protects against type 2 diabetes. Retrieved June 25, 2019, from https://www.medicalnewstoday.com/articles/321576.php
- Pilz, S., März, W., Wellnitz, B., Seelhorst, U., Fahrleitner-Pammer, A., Dimai, H. P., . . . Dobnig, H. (2008, October). Association of vitamin D deficiency with heart failure and sudden cardiac death in a large cross-sectional study of patients referred for coronary angiography. Retrieved June 25, 2019, from https://www.ncbi.nlm.nih.gov/pubmed/18682515
- Qi, L., Ma, W., Heianza, Y., Zheng, Y., Wang, T., Sun, D., . . . Manson, J. E. (2017, November). Independent and Synergistic Associations of Biomarkers of Vitamin D Status With Risk of Coronary Heart Disease. Retrieved June 25, 2019, from https://www.ncbi.nlm.nih.gov/pubmed/28882871
- Newman, T. (2018, March 10). How vitamin D protects against heart failure. Retrieved June 25, 2019, from https://www.medicalnewstoday.com/articles/321167.php
- Cerman, A. A., Solak, S. S., & Altunay, I. K. (2014, June 19). Vitamin D deficiency in alopecia areata – Aksu Cerman – 2014 – British Journal of Dermatology – Wiley Online Library. Retrieved June 25, 2019, from https://onlinelibrary.wiley.com/doi/abs/10.1111/bjd.12980
- Rasheed, H., Mahgoub, D., Hegazy, R., El-Komy, M., Abdel Hay, R., Hamid, M. A., & Hamdy, E. (2013, February). Serum ferritin and vitamin d in female hair loss: Do they play a role? Retrieved June 25, 2019, from https://www.ncbi.nlm.nih.gov/pubmed/23428658
- European Society of Endocrinology. (2018, May 21). Larger waistlines are linked to higher risk of vitamin D deficiency: Higher levels of belly fat are associated with lower vitamin D levels in obese individuals, according to data presented in Barcelona at the European Society of Endocrinology annual meeting, ECE 2018. ScienceDaily. Retrieved June 25, 2019 from www.sciencedaily.com/releases/2018/05/180521092731.htm
- Newman, T. (2018, May 21). Belly fat linked to vitamin D deficiency. Retrieved June 25, 2019, from https://www.medicalnewstoday.com/articles/321851.php?fbclid=IwAR0jeeRG5sbRic0DEFUXi6-v53Jle4_jBTWDULeWPJZv8VB9HS97Em-wbeo
- Vitamin D Deficiency. (2019, April 15). Retrieved June 25, 2019, from https://medlineplus.gov/vitaminddeficiency.html
- Kennel, K. A., Drake, M. T., & Hurley, D. L. (2010, August). Vitamin D deficiency in adults: When to test and how to treat. Retrieved June 25, 2019, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2912737/
Disclaimer: This information is not intended to be a substitute for professional medical advice, diagnosis or treatment and is for information only. Always seek the advice of your physician or another qualified health provider with any questions about your medical condition and/or current medication. Do not disregard professional medical advice or delay seeking advice or treatment because of something you have read here.