Mars and Venus and Vitamin D Deficiency
While many a bestseller has covered the topic of psychological differences between the sexes, women and men also differ in terms of their nutritional needs. Part of this difference stems from the generally larger body size and higher muscle mass of men. This is reflected in the Dietary Reference Intakes for which there is a higher recommendation for men compared to women. For example, men have greater needs for fats, protein, water, vitamins A, B1, B2, B3, C, K, magnesium and zinc. On the other hand, women need more iron, and during certain life phases such as pregnancy and breastfeeding, their nutrient needs increase beyond that of men (see Dietary Reference Intakes: The Essential Guide to Nutrient Requirements).
However, for many vitamins, nutrient needs are the same for both men and women. In many cases, this reflects a paucity of information supporting differing nutrient requirements rather than knowing that men and women have the same needs. This is an issue that Verdoia and co-workers attempted to address in their recent publication. They looked at vitamin D levels in 1800 patients undergoing a procedure to visualize the arteries leading to the heart (coronary angiography), which is indicated for heart disease. Vitamin D deficiency is often found in populations at risk of heart disease (see Ford et al.), and a causative role has been suggested (see review by Judd and Tangpricha).
The authors found that women had lower vitamin D levels. This was not too surprising, as the women undergoing coronary angiography were older. When the researchers adjusted their results for confounders such as age, they still found an increased risk of extremely low vitamin D levels (<10 ng/ml) for women compared to men. The authors also found that in women, lower vitamin D levels were independently associated with increased risk of coronary artery disease: it seems that low vitamin D is especially a problem for women as it raises risk of heart disease to a greater extent than for men.
What could be the cause of this gender difference? Some researchers suggest that fat-soluble vitamin D is preferentially stored in body fat (Wortsman and co-workers). Women, with their higher levels of body fat, may need more vitamin D to achieve better circulating levels. Mechanistic research has also shown that vitamin D can normalize menopausal changes that increase heart disease risk (Dong and associates). Perhaps in the coming years we will see different nutritional recommendations for vitamin D between men and women.
Verdoia M, Schaffer A, Barbieri L, Di Giovine G, Marino P, Suryapranata H, De Luca G. Impact of gender difference on vitamin D status and its relationship with the extent of coronary artery disease. Nutrition, Metabolism and Cardiovascular Diseases. 2015 5;25:464-70. http://dx.doi.org/10.1016/j.numecd.2015.01.009
Dong J, Wong SL, Lau CW, Lee HK, Ng CF, Zhang L, Yao X, Chen ZY, Vanhoutte PM, Huang Y. Calcitriol protects renovascular function in hypertension by down-regulating angiotensin II type 1 receptors and reducing oxidative stress. Eur Heart J, 33 (2012), pp. 2980–2990. http://www.ncbi.nlm.nih.gov/pubmed/22267242
Ford ES, Ajani UA, McGuire LC, Liu S. Concentrations of serum vitamin D and the metabolic syndrome among U.S. adults. Diabetes Care. 2005 May;28(5):1228-30. http://www.ncbi.nlm.nih.gov/pubmed/15855599
Judd SE, Tangpricha V. Vitamin D deficiency and risk for cardiovascular disease. Am J Med Sci. 2009 Jul;338(1):40-4. doi: 10.1097/MAJ.0b013e3181aaee91. http://www.ncbi.nlm.nih.gov/pubmed/19593102
Jennifer J. Otten, Jennifer Pitzi Hellwig, Linda D. Meyers, Editors. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements (2006). National Academies Press. http://www.nap.edu/catalog/11537/dietary-reference-intakes-the-essential-guide-to-nutrient-requirements
Jacobo Wortsman, Lois Y Matsuoka, Tai C Chen, Zhiren Lu, and Michael F Holick. Decreased bioavailability of vitamin D in obesity. Am J Clin Nutr September 2000 vol. 72 no. 3 690-693. http://ajcn.nutrition.org/content/72/3/690.abstract