|
|
Folic acid Magnesium Vitamin A Vitamin D Zinc | |
| Depletion or interference |
None known |
| Side effect reduction/prevention |
None known |
| Supportive interaction |
None known |
| Reduced drug absorption/bioavailability |
None known |
| Adverse interaction |
None known |
An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.
Vitamin A and folic acid
In a one-year study of predominantly malnourished women in India and Thailand,
medroxyprogesterone used for contraception was associated with increased blood levels of
vitamin A and folic acid.1 The clinical meaning of these changes remains
unclear.
Zinc and magnesium
In a group of 37 postmenopausal women treated with conjugated oestrogens and
medroxyprogesterone for 12 months, urinary zinc and magnesium loss was reduced in those women
who began the study with signs of osteoporosis and
elevated zinc and magnesium excretion.2 The clinical significance of this
interaction remains unclear.
Vitamin D
In a study of postmenopausal women, treatment with oestrogen alone increased vitamin D blood
levels, whereas oestrogen plus medroxyprogesterone lowered vitamin D back to the level seen
without oestrogen use.3 This outcome might suggest that medroxyprogesterone
interferes with beneficial effects oestrogen may have on vitamin D metabolism and vitamin D
supplementation would be called for. However, some research has not found the addition of
vitamin D to oestrogen/progestin combinations to be helpful.4 Therefore, while many
doctors recommend 400 IU vitamin D to women taking oestrogen/progestin combination hormone
products, the efficacy of such supplementation has not been proven.
1. Joshi UM, Virkar KD, Amatayakul K, et al. Impact of hormonal contraceptives vis-a-vis non-hormonal factors on the vitamin status of malnourished women in India and Thailand. World Health Organization: Special Programme of Research, Development and Research Training in Human Reproduction. Task Force on Oral Contraceptives. Hum Nutr Clin Nutr 1986;40:205–20.
2. Herzberg M, Lusky A, Blonder J, Frenkel. The effect of estrogen replacement therapy on zinc in serum and urine. Obstet Gynecol 1996;87:1035–40.
3. Bikle DD, Halloran BP, Harris ST, Portale AA. Progestin antagonism of estrogen stimulated 1,25-dihydroxyvitamin D levels. J Clin Endocrinol Metab 1992;75:519–23.
4. Komulainen M, Tuppurainen MT, Kroger H, et al. Vitamin D and HRT: no benefit additional to that of HRT alone in prevention of bone loss in early postmenopausal women. A 2.5-year randomized placebo-controlled study. Osteoporosis Int 1997;7:126–32.
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