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 Guessing What's Next for Vitamin D, Part Two The list of conditions treated by an increase in vitamin D continues to grow. By Jacob Schor, ND Editor's note: Part one of "Guessing What's Next for Vitamin D" appeared in the November 2006 issue of Naturopathy Digest. Fertility and Related Topics Vitamin D plays a role in fertility. This should seem rather obvious, as most plants and animals time their reproductive cycle with the seasons. The season of a woman's birth influences how old she will be when she enters menopause. Women born in March have the latest menopause, while women born in October have the earliest. On average, there is about a 15-month difference: Women born in October reach menopause at over 50 years of age, compared with less than 49 years for women born in March.43Although we usually don't think about it in humans, there is a seasonal variation to our conception. Conception rates are lowest during the dark winter months and peak during the summer months.44 Even human artificial insemination is more successful during the winter months, October through March, with the best results in November.45 When male rats are made vitamin D-deficient in experiments, they become infertile. Fertility can be restored by supplementing with vitamin D or calcium.46 PMS and LPDD Late luteal-phase dysphoric disorder (LPDD), which I suspect is a fancy descriptive for PMS-related depression, gets worse during the winter. Pain and swelling associated with menses don't appear to change with the season,47 but depressive symptoms surely do.48 Early Puberty: There is an unexplained tendency for young girls to reach puberty at progressively earlier ages. This is most noticeable in girls in Western countries and most pronounced in girls of African descent in these countries. Though many theories suggest exogenous estrogen exposure, consider that vitamin D deficiency is more common in African-American girls than Caucasian girls. It would be easy to jump to the assumption that vitamin D deficiency played a role in this earlier puberty. Yet, at least one study points out that living further north delays the onset of puberty.49 Could lowered fertility rates in industrialized countries be related to increasing levels of D deficiency as people get less sun exposure? Perhaps. Immune Function: White blood cell counts fluctuate with the seasons and this might be part of the reason for seasonal infectious disease variability.50 It isn't clear whether this variability is caused by fluctuating D levels. In rats, the leukocyte count and absolute lymphocyte content are highest in spring, while eosinophils peak in autumn, and neutrophils and monocytes peak in winter.51 Colds, Flu and Other Winter Cooties: Colds and flu are more prevalent in the winter. I don't need PubMed to notice that. Could this seasonality be a D deficiency? Does vitamin D status help people fight infection? Perhaps. Several studies have shown vitamin D triggers the human cathelicidin antimicrobial peptide gene, better known as the CAMP gene. This CAMP gene is part of the innate immune system and provides the rapid response used to repel assaults from numerous infectious organisms, including bacteria, viruses, fungi and parasites.52-53 A March 2006 study showed that by triggering this CAMP gene and stimulating these antibiotic-like chemicals, vitamin D is useful for fighting tuberculosis (TB). Blood from African-Americans contains less D and is less capable of mounting this type of defense. This explains why they are more susceptible to TB.54 While vitamin D deficiency is common among African-American children in our country, it isn't as common in Africa. Sure, they get rickets - not from D deficiency, but instead from calcium deficiency.55 In Europe, massive single doses of vitamin D are given in what is called Stoss therapy. Used initially to treat D-deficiency rickets, these are jumbo, several hundred thousand IU of vitamin D at a time. Despite the absence of published clinical data, Stoss Therapy is becoming popular for acute infectious disease. An Internet search finds multiple Web sites promoting Stoss therapy for anything from the common cold to bird flu. On his Web site, John Cannell, MD, the vitamin D guru, summarizes a 1994 study written by Dr. P.K. Rehman.56 "In 1994, Dr. Rehman gave 60,000 units of vitamin D a week to 27 children (ages 3-12) with frequent childhood infections and compared them to controls. The children also had elevated alkaline phosphatase, which usually indicates vitamin D deficiency. He gave the kids vitamin D for six weeks along with calcium. Within a few weeks, 'infections were fully controlled and no recurrences were reported for six months.' The kids just stopped getting sick! ... 9,000 units a day of vitamin D for six weeks should bring most vitamin D-deficient children to 50 ng/ml, probably higher."57 Perhaps the reason people get colds and flu in the winter is not because it's cold, rainy and snowy. Perhaps it's because, like many of these other seasonal illnesses, vitamin D levels are lower during that time of the year, weakening our defenses against infection. Asthma and T-helper Cells: In Greece, more young kids get hospitalized during the winter through spring months with asthma, but then there is a clear peak in admissions in May.58-59 Could this just be lousy air quality in the winter and allergies in the spring? There is no question asthma is triggered by air pollution60 and air particulates.61 Current opinion seems to be that although vitamin D is useful for some autoimmune diseases, it doesn't help asthma. At this time, the link between D and IBD, RA, MS and DM is pretty much accepted. The theory is that D is useful for these autoimmune diseases because it inhibits the development and function of Th-1 cells and induces other T-helper cells, including Th-2 cells.62 The idea of down-regulating Th-1 cells and inducing Th-2 cells is another one of those big concepts in medicine that came along after I graduated school; this gives me an excuse to omit further discussion about it. Suffice to say, add vitamin D to your lists of things useful in shifting from Th-1 to Th-2 predominance. SAD: The Obvious Link to D Deficiency The most obvious condition that begs mention is seasonal affective disorder (SAD). By definition, SAD is seasonal, getting worse as vitamin D levels decline with decreasing sun exposure in the winter as people get depressed.63 In one study, supplementation with 800 IU per day of vitamin D didn't help.64 But, in another study, doses of 400 to 800 IU made a difference.65 Yet another study used 100,000 IU and this dose definitely helped. This later study compared vitamin D supplementation against light therapy. "All subjects receiving vitamin D improved in all outcome measures. The phototherapy group showed no significant change in depression scale measures."66 Eating disorders, particularly bulimia, also worsen in the winter and perhaps similar doses of vitamin D should be considered for these patients.67 Here in Denver, sunny as it might be, come late winter, a great many people like to fly down to Mexico for a week to get some sun. Given the estimate that a day on the beach might generate 10,000-20,000 IU of vitamin D, I figure a week at the beach is equivalent to about 100,000 IU. Thus, the study that used the 100,000 IU dose has a certain charm to it. I have little doubt that these returning vacationers look happier than anyone else in town. OK, So It's Guesswork Some of these links are weak, some on the verge of acceptance. Given the low toxicity profile of vitamin D, I find myself more and more often looking a patient in the eye and telling them, "Vitamin D won't hurt, and it just might help you feel better." References
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All Rights Reserved, Naturopathy Digest, 2011.
Date Last Modified - Friday, 17-Oct-2008 12:10:27 PDT
About the Author: Jacob Schor, ND, graduated with a Bachelor of Science degree from Cornell University and received his naturopathic training at National College of Naturopathic Medicine. He currently practices at the Denver Naturopathic Clinic. E-mail Dr. Schor at 