Researchers from the Medical University of Graz have found that in addition to helping you absorb calcium and being good for your bones, vitamin D may in fact regulate human fertility.
Vitamin D may influence the sex hormones estrogen and progesterone in women and testosterone in men. Higher levels of vitamin D may improve the frequency of menstrual periods, helpful for women who suffer irregular periods. It could also improve semen quality, making conception more likely.
In fact, mice that were devoid of vitamin D had numerous health problems including decreased sperm counts, sperm that couldn’t swim properly and abnormalities of the testes, ovaries and uterus.
Similar effects are seen in women with polycystic ovary syndrome (PCOS). When they have low levels of vitamin D they have a greater risk of metabolic and hormone disorders and obesity so supplementing PCOS patients with vitamin D tablets may regulate their hormones and weight and allow them to conceive naturally.
The study, published in the European Journal of Endocrinology, found that sperm levels peaked in the summer months and women don’t ovulate as much in the winter months. This tallies with statistics that show that conception rates fall in the winter months in Northern European countries.
Sources of Vitamin D
Sources of vitamin D include:
- Eggs
- Liver
- Oily fish
- Cheese
- Mushrooms grown under ultraviolet light
- Fortified breakfast cereals
- Fortified milk
- Fortified margarine.
However, only about 20% of the required amount of vitamin D can be obtained from these food sources – the rest can only be got from UVB rays from the sun.
Oliver Gillie from the Health Research, said
“I would say to couples (in Northern European countries) hoping to get pregnant to arrange a sunshine holiday, or get into the garden in the summer as often as they can...before you go down the route of expensive IVF treatment.”
Sunscreen Reduces Vitamin D Absorption Ten Fold
Those couples in hotter countries should also be warned that the routine use of sunscreen prevents the absorption of vitamin D and so could theoretically contribute to fertility problems. Some medical professionals today advise that people should be getting small amounts of exposure to the sun without sunscreen.
Bone doctor, John Wark, of the Royal Melbourne Hospital, said
“Crisis is a pretty emotive word but all the available information would suggest this (sunscreen advice) is likely to impact badly on the health of older people unless we can find a solution.”
A fair skinned person can safely have a few minutes per day of sun exposure without sunscreen. A person with a tanned complexion can have 15 to 20 minutes per day and a black person can have more than that (as it takes dark skin longer to absorb vitamin D). The key points to remember are avoiding long periods of time in direct sunlight, wearing a T shirt to cover your skin, wearing sunhats and finding a shady spot (after you have had your allotted time without sunscreen).
If you don’t want to try this due to concerns about skin cancer or you can’t get outside much, you could get your vitamin D allowance via a tablet supplement instead. If you are having fertility problems, it is certainly worth trying these before shelling out thousands in IVF fees.
Sources:
- Vitamin D and fertility-a systematic review. Eur J Endocrinol January 24, 2012. Abstract: http://eje-online.org/content/early/2012/01/24/EJE-11-0984.abstract?sid=b081dcaa-0a6a-4458-a407-1378ccd7e97c
- Sunny break may be alternative to IVF: How the sunshine vitamin can help boost fertility, Daily Mail, 30th January 2012.
- Vitamin D, National Institutes of Health. Web. 30th January 2012.
- Chronic sunscreen use decreases circulating concentrations of 25-hydroxyvitamin D. A preliminary study. Arch Dermatol. 1988 Dec;124(12):1802-4. Abstract: http://www.ncbi.nlm.nih.gov/pubmed/3190255?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum
- Be sun-smart, avoid bone D-generation risks, The Age. 9th December 2007.
- Time in the Sun: How Much Is Needed for Vitamin D? US News Health. June 23rd, 2008. http://health.usnews.com/health-news/family-health/heart/articles/2008/06/23/time-in-the-sun-how-much-is-needed-for-vitamin-d
Joanna Karpasea-Jones - I have been a health writer since 1997 when I published my own newsletter, SHOTS. I have written 2 books on childhood health, and write ...
