Print Digg


Sun: The Natural Source of Vitamin D

Thursday, February 02, 2012

Sunlight is the light of life. It's as important as air and water and it'is the best source of Vitamin D. We all need 10-15 minutes a day of sun on as much skin as we can legally get away with exposing, while wearing our sun glasses.  

Dr. Michael Holick, one of the foremost Vitamin D experts, estimates that vitamin D deficiency is the most common medical condition in the world.  John Cannell, MD, the Executive Director of the Vitamin D Council has been quoted as saying, “Humans make thousands of units of self-limiting Vitamin D within minutes of whole body exposure to sunlight. From what we know of nature, it is unlikely such a system evolved by chance.”

Dr. Frank Lipman, internationally recognized expert in the fields of Integrative and Functional Medicine and a practicing physician says, “For hundreds of thousands of years, man has lived with the sun: our ancestors were outdoors far more often than indoors. We developed a dependence on sunshine for health and life, so the idea that sunlight is dangerous does not make sense. How could we have evolved and survived as a species, if we were that vulnerable to something humans have been constantly exposed to for their entire existence?” 

There are only two ways to receive vitamin D in the amounts necessary for health. UVB exposure from sunlight and vitamin D supplementation:


Since this is the way nature intended, it should be considered the method of choice. Vitamin D synthesis occurs faster in individuals with fair skin, the darker the skin the longer it takes for sun on skin to produce vitamin D.  According to the Vitamin D Council, sunscreen with an SPF as low as 8 can block as much as 95% of vitamin D production. 

New Adequate Daily intake (AI) for vitamin D

Children and adults up to the age of 70 years – 600 IU
Seniors 70+ years – 800 IU

Most vitamin D researchers think these amounts are inadequate since these recommendations are based solely on vitamin D and bone health studies. Vitamin D influences a much wider array of physiological processes than simply maintaining bone health and normal calcium metabolism.  They suggest that for proper functioning, a healthy human body utilizes around 3,000-5,000 IU of vitamin D per day, indicating the current recommended intakes are not high enough to raise and / or maintain the vitamin D levels necessary for optimal health.

The US Government tolerable Upper Intake Level (Ul) for vitamin D has recently been increased from 2,000 IU per day to 4,000.  This is an improvement but still may be on the low side, given all of the recent science, particularly for those with extra weight or who are obese.

The self-limiting amount produced by sun on skin seems to be about 10,000 IU per day.

Supplemental vitamin D comes in two forms: cod liver based oil and dry powder lanolin-based water-soluble vitamin D.  As far as we know, both are equally absorbed and metabolized by the body.  Vitamin D3 is the type of vitamin D the body naturally produces from sun exposure on skin therefore the type used in most vitamin D supplements.  Vitamin D2 is produced naturally from yeast and is not as readily absorbed.

Vitamin D and Weight Gain

Recent studies link vitamin D deficiency to weight gain and all of the degenerative diseases associated with excess weight, including diseases of the eye. 

Ellen Troyer, MT MA
Biosyntrx CEO / Chief Research Officer



My tan has faded and The Royal Hawaiian Eye Meeting is now a cherished education memory.  The good news is that a week of appropriate amounts of sun on skin was good for both physical and mental health. 

I'm sitting at my desk in Colorado watching a beautiful snow storm blow over Cheyenne Peak, which is putting a big smile on the faces of all skiers. The Western mountains have not had a lot of snow this season and more good news is that the sun will come back tomorrow - or the next day, as it does in the Rockies.    

Enjoy the coming weekend and spend some time playing outside.   It will make you happy.

FYI: Vitamin D deficiency has been linked to a higher risk of developing AMD, so Biosyntrx Macula Complete multiple includes 2,000 IU of vitamin D3, our less potent multiple, Oculair, includes 1,200 IU of vitamin D3 and our dry eye formulation, BioTears, includes 168 IU of vitamin D from cod liver oil - per suggested daily dose.   


  1. Prentice, A. Vitamin D deficiency: a global perspective. Nutr Rev. 2008 Oct; 66 (10 Suppl 2): S153-64.
  2. Pettifor, J. M. Vitamin D &/or calcium deficiency rickets in infants & children: a global perspective. Indian J Med Res. 2008 Mar; 127 (3): 245-9.
  3. Holick, M. F. Chen, T. C. Vitamin D deficiency: a worldwide problem with health consequences. Am J Clin Nutr. 2008 Apr; 87 (4): 1080S-6S.
  4. University of California Riverside More Than Half the World’s Population Gets Insufficient Amounts of Vitamin D, Says UC Riverside Biochemist. 15 July 2010;
  5. Science Daily Millions Of U.S. Children Low In Vitamin D. 3 Aug 2009;
  6. Schwalfenberg, G. K. Genuis, S. J. Hiltz, M. N. Addressing vitamin D deficiency in Canada: a public health innovation whose time has come. Public Health. 2010 Jun; 124 (6): 350-9.
  7. Kuriacose, R. Olive, K. E. Prevalence of vitamin D deficiency and insufficiency in northeast Tennessee. South Med J. 2008 Sep; 101 (9): 906-9.
  8. Bandeira, F. Griz, L. Dreyer, P. Eufrazino, C. Bandeira, C. Freese, E.Vitamin D deficiency: A global perspective. Arq Bras Endocrinol Metabol. 2006 Aug; 50 (4): 640-6.
  9. Ardestani, P. M. Salek, M. Keshteli, A. H. Nejadnik, H. Amini, M. Hosseini, S. M. Rafati, H. Kelishadi, R. Hashemipour, M. Vitamin D status of 6- to 7-year-old children living in Isfahan, Iran. Endokrynol Pol. 2010 Jul-Aug; 61 (4): 377-82.
  10. Bener, A. Al-Ali, M. Hoffmann, G. F. Vitamin D deficiency in healthy children in a sunny country: associated factors. Int J Food Sci Nutr. 2009; 60 Suppl 560-70.
  11. Teale, G. R. Cunningham, C. E. Vitamin D deficiency is common among pregnant women in rural Victoria. Aust N Z J Obstet Gynaecol. 2010 Jun; 50 (3): 259-61.
  12. Harinarayan, C. V. Joshi, S. R. Vitamin D status in India--its implications and remedial measures. J Assoc Physicians India. 2009 Jan; 5740-8.
  13. Andersen, R. Molgaard, C. Skovgaard, L. T. Brot, C. Cashman, K. D. Chabros, E. Charzewska, J. Flynn, A. Jakobsen, J. Karkkainen, M. Kiely, M. Lamberg-Allardt, C. Moreiras, O. Natri, A. M. O'Brien, M. Rogalska-Niedzwiedz, M. Ovesen, L. Teenage girls and elderly women living in northern Europe have low winter vitamin D status. Eur J Clin Nutr. 2005 Apr; 59 (4): 533-41.
  14. Rodriguez Sangrador, M. Beltran de Miguel, B. Quintanilla Murillas, L. Cuadrado Vives, C. Moreiras Tuny, O. [The contribution of diet and sun exposure to the nutritional status of vitamin D in elderly Spanish women: the five countries study (OPTIFORD Project)]. Nutr Hosp. 2008 Nov-Dec; 23 (6): 567-76.
  15. Bhattoa, H. P. Bettembuk, P. Ganacharya, S. Balogh, A. Prevalence and seasonal variation of hypovitaminosis D and its relationship to bone metabolism in community dwelling postmenopausal Hungarian women. Osteoporos Int. 2004 Jun; 15 (6): 447-51.
  16. Allali, F. El Aichaoui, S. Khazani, H. Benyahia, B. Saoud, B. El Kabbaj, S. Bahiri, R. Abouqal, R. Hajjaj-Hassouni, N. High prevalence of hypovitaminosis D in Morocco: relationship to lifestyle, physical performance, bone markers, and bone mineral density. Semin Arthritis Rheum. 2009 Jun; 38 (6): 444-51.
  17. Du, X. Greenfield, H. Fraser, D. R. Ge, K. Trube, A. Wang, Y. Vitamin D deficiency and associated factors in adolescent girls in Beijing. Am J Clin Nutr. 2001 Oct; 74 (4): 494-500.
  18. Peters, B. S. dos Santos, L. C. Fisberg, M. Wood, R. J. Martini, L. A.Prevalence of vitamin D insufficiency in Brazilian adolescents. Ann Nutr Metab. 2009; 54 (1): 15-21.
  19. Judkins, A. Eagleton, C. Vitamin D deficiency in pregnant New Zealand women. N Z Med J. 2006; 119 (1241): U2144.
  20. Mansoor, S. Habib, A. Ghani, F. Fatmi, Z. Badruddin, S. Siddiqui, I. Jabbar, A. Prevalence and significance of vitamin D deficiency and insufficiency among apparently healthy adults. Clin Biochem. 2010 Sep 27;
  21. Gordon, C. M. DePeter, K. C. Feldman, H. A. Grace, E. Emans, S. J.Prevalence of vitamin D deficiency among healthy adolescents. Arch Pediatr Adolesc Med. 2004 Jun; 158 (6): 531-7.
  22. Gordon, C. M. Feldman, H. A. Sinclair, L. Williams, A. L. Kleinman, P. K. Perez-Rossello, J. Cox, J. E. Prevalence of vitamin D deficiency among healthy infants and toddlers. Arch Pediatr Adolesc Med. 2008 Jun; 162 (6): 505-12.
  23. Davis, W. Rockway, S. Kwasny, M. Effect of a combined therapeutic approach of intensive lipid management, omega-3 fatty acid supplementation, and increased serum 25 (OH) vitamin D on coronary calcium scores in asymptomatic adults. Am J Ther. 2009 Jul-Aug; 16 (4): 326-32.
  24. Seki, T. Yamamoto, M. Ohwada, R. Takano, K. Kure, M. Sekine, H. Katsura, Y. Sato, K. Successful treatment of postsurgical hypoparathyroidism by intramuscular injection of vitamin D3 in a patient associated with malabsorption syndrome due to multiple abdominal surgeries. J Bone Miner Metab. 2010 Mar; 28 (2): 227-32.
  25. Garland, C. F. Gorham, E. D. Mohr, S. B. Garland, F. C. Vitamin D for cancer prevention: global perspective. Ann Epidemiol. 2009 Jul; 19 (7): 468-83.