The relationship between folic acid, vitamin B12, and vitamin B6 intakes and depression in women who use hormonal oral contraceptives: 2003–2008 National Health and Nutrition Examination Survey

Abstract

BackgroundDepression is one of the leading causes of disability and mortality worldwide. Women are at increased risk for depressive disorders. Diet has been shown to have a significant impact on mental health and outcomes. Many studies have associated oral contraceptive (OC) use with impaired status of key nutrients identified to affect normal brain function and neurotransmitter activity, including folate, vitamins B6 and B12. This study aimed to investigate the relationship between nutrient intake and depression in OC users.MethodsSelf‐reported dietary folate, vitamin B12, and vitamin B6 intakes were used to determine the relationship between nutrient intakes and depression in women who used OCs (n = 34) in a selected cohort of women aged 18 to 49 years of age (n = 409) from the 2003–2008 National Health and Nutrition Examination Survey. The relationships between OC use, vitamins, and depression were tested using χ2 and independent samples t‐tests.ResultsWomen who used OCs were 10.2% more likely to be depressed than women who did not use OCs (45.7% vs. 35.5%, p < .001). Women who used OCs consumed less folate (558.31 ± 256.65 μg vs 592.81 ± 418.72 μg) and vitamin B12 (6.74 ± 5.75 μg vs 12.32 ± 48.85 μg) than women who did not use OCs (p < .001). Conversely, women who used OCs consumed more vitamin B6 (5.53 ± 14.78 mg vs 3.73 ± 11.24 mg) than consumed by women who did not use OCs (p < .001). In addition, both groups of women achieved average intakes that were higher than the RDA for all three vitamins. Depression was correlated to quartile levels of vitamin intake for all women (p <.001). No benefit against depression was observed with inadequate intakes or intakes that exceeded the RDAs for women who did not use OCs. In fact, women in this group whose folate and vitamin B6 intakes exceeded the RDA ( the fourth quartile intake levels) were 2% and 3.9%, respectively, more depressed than those who consumed less than the RDA (the first quartile, p < .001). For women who did not use OCs, vitamin B12 intakes exceeding the RDA were associated with 1.3% less depression than intakes below the RDA (p < .001). Women who used OCs were 10.2%, 9.7%, and 11.1% more likely to be depressed than women who did not use OCs when they consumed less than the RDA for folate, vitamin B12, and vitamin B6, respectively, as seen in the first quartile (p < .001). Compared to the first three intake quartiles for all three vitamins, women who used OCs and who consumed within the fourth quartile (which exceeded the RDAs for folate, vitamin B12, and vitamin B6) appeared to be less depressed (13%, 75%, and 7%, respectively) than those women who consumed below the RDA (p < .001). Interestingly, the least amount of depression in women who used OCs was found when vitamin B6 intake levels were at or somewhat above the RDA, as seen with the second and third quartile groups.ConclusionCurrently, there are no specific nutrition recommendations to prevent or treat depression or mood disorders. The results suggest that dietary intake of folate, vitamins B6 and B12 has an impact on mental health and mood, and that significant differences in average vitamin intake exist between women who use OCs and women who do not use OCs. Future studies are needed to determine if depression results from or could be reduced with a woman's dietary intake. Further research would strengthen the understanding of these relationships by including laboratory values to assess vitamin status and overall bioavailability of these nutrients among OC users.