I recently read about the current recommended amount of Vitamin D required was all along wrong. And how much is enough? Are we all getting enough Vitamin D even at this low dosage that we required today? There are many unanswered questions and let’s explore them in this post.
This Vitamin D issue kept me thinking since the day when I did my first Vitamin D blood test. It was to determine the level of my Vitamin D in my body. I was surprised to know that I was insufficient in Vitamin D level. There is one more level below insufficient, that is deficiency. I was absolutely shocked. Living in the tropics means we are getting lots of sunshine, almost 365 days we should be getting Vitamin D. And in fact, the sunlight is the major source of Vitamin D. If this main source is not good enough, what about the effect from food. And how could ensure that we are getting enough of Vitamin D.
I spoke to my Family Physician regarding the insufficiency level, about my puzzle. In short the Vitamin D issue. She was so certain that a stone throw you would hit a handful who are deficient in Vitamin D. It is also documented in journal by Michael Rathish Nair and Arun Maseeh in their article “Vitamin D: The “sunshine” vitamin“” about the Vitamin D insufficiency concern. It was stated that insufficiency is affecting 50% of worldwide population and 1 billion is deficient. And in many journal both research and review, the health issue that was impacted by Vitamin deficient is highlighted again and again. It is a true and real worldwide issue, affecting humans globally. Why are not getting enough?
What is Vitamin D?
As a pure Science student since Secondary School, to be more specific, I was a pure Biology students. All the way I studied Biology till University level. As such, I have a good understanding of the of Vitamin D from its structure to the role and so on.
Let’s take a closer look at what is Vitamin D.
Most of us know that Vitamin D is an organic compound that is fat soluble. I am not going into the organic structure of why it is fat soluble and so on. Let’s stop it here, at this straightforward fact that is a common knowledge to most.
Next, it is an essential compound for maintenance good health. When insufficient, disorders might result.
Role of Vitamin D
The vitamin has a role in both skeletal and non skeletal benefits. It is clear that Vitamin D has an important role in maintaining the bone density and reduce fractures risk, protecting against osteoporosis.
While non skeletal benefits, though more research are required but it is evidence that it may include having a role in the immune system, protect against cardiovascular, reduce risk of diabetes, cancer, multiple sclerosis, allergy & asmthma, infection, mental illness, renal diseases and lessen musculoskeletal pain.
Where could we get Vitamin D?
One important and main source of Vitamin D is from the sun. It will be absorbed as an inactive form and subsequently changed to an active form that that our body could absorbed. This form is the most effect way of getting Vitamin. It is proven by Tom D. Thacher, MD and Bart L. Clarke, MD “Vitamin D Insufficiency“. But many of us would be putting on sun block. This was rightly pointed out by my Family Physician and was proven by Matsuoka LY et al in their preliminary research too. But I argue that the use of sunscreen with my Family Physician since it result in a drop of Vitamin D, shouldn’t it be avoided. Her reply was, on the other hand, without the sunscreen, skin cancer arises. At this point, the benefit seems to outweigh the risk. This was also highlighted by Burnett ME, Wang SQ “Current sunscreen controversies: a critical review“.
In another research carried out by Holick MF “Vitamin D: its role in cancer prevention and treatment“, it was observed that the adults living in the Southern States such as Alabama who were more exposed to the sun, were yet less likely to die from cancer than those in the Northen States, Vermont, New Hampshire and Massachusetts. It seems that the increased of Vitamin D from sunshine protected them against cancer. The higher cancer rate in the north than south was first noted by n Garland et al. (1991, 1989) which subsequent more similar observation was noted.
The other source would be from food. It is noted that not many food contains the natural source of Vitamin D as pointed out by Michael F Holick and Tai C Chen in “Vitamin D deficiency: a worldwide problem with health consequences“. It comes mainly from oily fish such as Salmon mackerel and herring; cod-liver oil and sun-dried mushrooms. What made it worse was fishes that were reared has 80% lesser Vitamin D compared to those in the wild.
Are we going to restrict ourselves to supplement as the last resort? There was a peer review carried out by Stuart T. Haines, Pharm.D., FCCP, and Sharon K. Park, Pharm.D. “Vitamin D Supplementation: What’s Known, What to Do,
and What’s Needed” regarding this point. In this review, the team examine the benefits of vitamin D supplementation, the potential risks, to provide practical advice regarding dosing, and to alert readers the ongoing clinical trials. A pretty comprehensive review article. In the article, it concluded that there wasn’t enough research evidence to conclude that Vitamin D would protect individual from various diseases but unlikely to cause harm. It is also highlighted that for individual who are insufficient or even deficiency, supplement is an option.
Based on my experience, the supplement indeed was useful. With a tab (1ooo IU) three times a day for about a month and subsequently, reduced to 2 tabs in the morning for about a month too.
It did increase to the borderline sufficient level.
Current Vitamin D Recommendation
The last revised recommendation was in 2010. It is recommended that age 1- 70, includeing the pregnant or breastfeeding women with a recommended daily allowance (RDA) at 600 IU while those over 71 years old at 800 IU. And for infants aged 0-12 months, 1,000 IU daily.
Are we getting enough today?
I am not one who avoid the sun at all cost and I don’t usually put on a sun screen from head to toe. Neither am I one who enjoy the sun. I like all food. I don’t avoid any food. With all these, I am still insufficient of this Vitamin.
So are we getting enough today? From what we have discovered from the various research and review article, it is pretty indicative that we aren’t getting enough. And from a real life example, that is me.
I went on to research more on this sub-topic and look into which group is at higher risk of insufficiency.
A research Garland et al (2006) conducted in the United States noted that deficiency was present in all races, even in temperate areas. And Asia has not been spared. In addition, the absorption of Vitamin D is variable and dependent on gender, age and many other factors.
On the contrary, a research carried out by Tan Tock Seng Hospital by Robert C. Hawkins et al (2009) in Singapore in Chinese, Malay and Indian arguing that we may have enough of Vitamin D. They argue that the blood test done today is mainly on the inactive form of Vitamin D, as such the active form of Vitamin D may be at a sufficient level. Since they did not carry out any research on the level of active form of Vitamin D in the Singapore population, I am skeptical to this argument as it is not conclusive. But what I draw from this research is that it is indicating that though this study clear demonstrated the differences between sexes and races in the inactive form, nontheless, gender, sex and age aren’t reliable indicator to determine who is at risk. It is personal factors, such as skin pigmentation, food, obesity, clothing, dressing style, and cultural habits, are the likely source of the differences, between both races and sexes.
Who is at risk?
There are certain groups of who are at risk of deficiency or insufficiency.
- Breastfed infants
- Older adults
- People with limited sun exposure
- People with dark skin
- People with inflammatory bowel disease and other conditions causing fat malabsorption
- People who are obese
- People who have undergone gastric bypass surgery
New Research Vitamin D Dosage Recommendation
According to the article “The Unbelievable Reason You’re Short On Vitamin D” published on 19 May 2015 by Meghan Rabbitt on preventive.com stated that the first research to indicate incorrect recommended daily allowance was by Paul J. Veugelers * and John Paul Ekwaru in Nutrients, titled “A Statistical Error in the Estimation of the Recommended Dietary Allowance for Vitamin D“.
Dr Mercola has also indicated that the RDA should be 10 times higher.
And it seems a latest research by Heaney et al has enough statistic to show that the 2010 recommendation was of an error.
In my opinion, the statistics though may indicate a need for a higher dosage but it isn’t conclusive. There is more work required. What exactly is the recommendation. It seems for from the various research the only conclusive argument to be drawn is ‘Yes, there is a need to increase the amount.’ But to what amount there is clearly more work to be done to determine the level.
Moreover, are we certain that the high dosage causes no harm. The threshold of Vitamin toxicity has not been established. The highest level that was done that causes no harm is at 50 mug (2000 IU)/d.
And how beneficial it is to raise the amount of Vitamin D intake?
I see that there are many unanswered questions. The authority should not be rash to rush into a new recommendation till more research is carried out.
As for the source of Vitamin D, moderate dose of sunlight is still important. The key to prevent cancer per the research is to ensure a sufficient level in the body. So monitor via blood test for both the active and inactive Vitamin D. When necessary increase with Vitamin D supplement.
Matsuoka LY, Ide L, Wortsman J, MacLaughlin JA, Holick MF. Sunscreens suppress cutaneous vitamin D3 synthesis. J Clin Endocrinol Metab. 1987;64:1165–8
Burnett ME, Wang SQ Current sunscreen controversies: a critical review. Photodermatol Photoimmunol Photomed. 2011 Apr;27(2):58-67
Cynthia Aranow, MD Vitamin D and the Immune System. J Investig Med. 2011 Aug; 59(6): 881–886.
Garland, C.F., Comstock, G.W., Garland, F.C., Helsing, K.J., Shaw, E.K., Gorham, E.D., 1989. Serum 25-hydroxyvitamin D and colon cancer: eight-year prospective study. Lancet 2, 1176–1178.
Garland, C.F., Garland, F.C., Gorham, E.D., 1991. Can colon cancer incidence and death rates be reduced with calcium and vitamin D? Am. J. Clin. Nutr. 54, 193S–201S.
Vieth R The role of vitamin D in the prevention of osteoporosis. Ann Med. 2005;37(4):278-85.
Utiger R. The need for more vitamin D. N Engl J Med. 1998;338(12): 828–829
Cedric F. Garland, DrPH, Frank C. Garland, PhD, Edward D. Gorham, PhD, MPH, Martin Lipkin, MD, Harold Newmark, ScD, Sharif B. Mohr, MPH, and Michael F. Holick, MD, PhD The Role of Vitamin D in Cancer Prevention. Am J Public Health. 2006 February; 96(2): 252–261.
Fraser DR Vitamin D-deficiency in Asia. J Steroid Biochem Mol Biol. 2004 May;89-90(1-5):491-5.
Robert C. Hawkins 25-OH Vitamin D3 Concentrations in Chinese, Malays, and Indians. Clinical ChemistrySeptember 2009 vol. 55 no. 9 1749-1751
S. Balasubramanian Vitamin D deficiency in breastfed infants & the need for routine vitamin D supplementation. Indian J Med Res. 2011 Mar; 133(3): 250–252.
Ran Zhang and Declan P Naughton. Vitamin D in health and disease: Current perspectives. Nutrition Journal 2010, 9:65.
Malone M. Recommended nutritional supplements for bariatric surgery patients. Ann Pharmacother 2008;42:1851-8.
Compher CW, Badellino KO, Boullata JI. Vitamin D and the bariatric surgical patient: a review. Obes Surg 2008;18:220-4.
Paul J. Veugelers * and John Paul Ekwaru. A Statistical Error in the Estimation of the Recommended Dietary Allowance for Vitamin D. Nutrients 2014, 6(10), 4472-4475
Dr Mercola. The Real RDA for Vitamin D Is 10 Times Higher Than Currently Recommended. 10 May 2015. Retrieved from http://articles.mercola.com/
Meghan Rabbitt. The Unbelievable Reason You’re Short On Vitamin D. 19 May 2015. Retrieved from http://www.prevention.com
Heaney R., et al. Letter to Veugelers, P.J. and Ekwaru, J.P., A Statistical Error in the Estimation of the Recommended Dietary Allowance for Vitamin D. Nutrients 2014. Nutrients, 2015.