HRT: How your nutrient requirements can be impacted by Hormone Replacement Therapy.

Written by Dr. Robin Andrews and reviewed by Dr. Harriet Connell

HRT is generally recognised as the gold standard treatment for managing difficult, often life-affecting, perimenopause and menopause symptoms. Typically, these include hot flushes, sleep problems, mood changes, weight gain, brain fog, vaginal dryness, low libido and joint pain - and HRT is recommended by both The National Institute for Health and Care Excellence (NICE) and the British Menopause Society (BMS) as a first line of treatment to alleviate these side effects. In short, HRT helps to replace hormones – primarily oestrogen and progesterone and/or in some cases testosterone - that your body is no longer producing as you go through the perimenopause and menopause. Around 15% of women in the UK aged between 45 to 64 are currently prescribed HRT¹ and many describe it as having an overwhelmingly positive effect on their well-being and mood. Evidence also shows that as well as easing perimenopause and menopause symptoms, HRT can reduce the risk of osteoporosis (fragile, brittle bones) by increasing levels of oestrogen² and, for some women who start taking it early in their menopause, cardiovascular disease.³
As with any medication, some women can experience side effects when using HRT which include headaches, nausea, bloating, breast tenderness, muscle cramps and unexpected vaginal bleeding. In fact, around 33% of women report side effects,⁴ eight out of 10 abandon the medication completely within two to three years⁵ and 40 % give it up after just four months.⁵ If troublesome symptoms do persist your HRT type, dosage or mode of delivery (i.e. pill, patch, gel, spray or vaginal ring) can usually be changed and/or tweaked accordingly after a few months to help resolve any problems.⁶

How HRT can affect nutrient needs

One of the lesser-known effects, however, is the potential for oral HRT to change the way your body absorbs, stores and utilises essential vitamins and minerals. Many factors influence nutrient status including smoking, heavy drinking, chronic stress, illness, poor diet and many common medications, plus as we age, we simply don’t absorb some vitamins and minerals as efficiently as we once did. Results from the 2018 National Diet and Nutrition Survey show women between the ages of 50-59 are not getting enough folic acid, calcium, magnesium, potassium, selenium, iodine and copper.⁷ Research shows us that the hormones in oral HRT can potentially alter our requirements for key nutrients needed for optimum health including vitamin C, folate (vitamin B9), vitamin B12, vitamin B6 and the minerals selenium and zinc.⁸
Unfortunately, to date, there has been very little research to understand if body-identical transdermal forms of HRT (patches and gels) can have the same effect on nutrient requirements as oral HRT, but some research papers indicate that non-oral forms of hormonal contraception (like the injection or implant) have been shown to change nutrients in a similar way to the contraceptive pill.⁹,¹⁰ Furthermore, a link between the natural hormone shifts of a normal menstrual cycle has been shown to influence nutrient levels amongst women of pre-menopause age not taking exogenous hormones.¹¹

How do the hormones in oral HRT change the way our body interacts with nutrients? As with taking hormonal contraceptives like the combined oral contraceptive (COC) pill, using HRT changes our hormone levels, notably oestrogen and progesterone, in the body. This supplementation of exogenous hormones can cause a number of physiological changes in the body including:

1. Accelerated metabolism of active nutrients.

Evidence indicates that exogenous hormones like HRT and hormonal contraception accelerate the metabolic pathways that consume nutrients such as Vitamin C, leading to lower levels available for storage and use¹²

2. Impaired absorption through reduced capacity of transfer proteins.

Vitamin B12, vital for DNA synthesis and energy metabolism, is likely depleted through mechanisms that involve reduced binding capacity of a protein essential for B12 absorption in the stomach¹²,¹³

3. Reductions in co-enzymes responsible for forming active nutrient compounds.

Vitamin B6 levels are reduced due to the induction of enzymes like tryptophan oxygenase, leading to decreased availability of B6¹⁰

4. Excretion of key micronutrients. Exogenous oestrogens can lead to sodium retention and fluid accumulation.

The increased sodium retention can disrupt the balance of electrolytes such as magnesium and zinc, as these minerals are often excreted at higher rates to compensate for sodium accumulation¹²

5. The loss of certain nutrients can trigger cascading effects on others.

Nutrients are essential for our enzymes to function properly¹². Exogenous hormones like HRT can lower nutrient levels, potentially disrupting enzymatic processes, leading to deficiencies in other compounds. For example, vitamin B6 and magnesium are interdependent in several enzymatic reactions, meaning reductions in one can exacerbate deficiencies in the other.

Nutrients known to be affected by HRT

These are some of the nutrients your body may need more of if you are using oral HRT:

Vitamin B12

Studies have shown that this nutrient can deplete when taking oral HRT but the effect isn’t statistically significant when using transdermal HRT.¹⁴ B12 is a nutrient found in red meat, fish, liver, eggs and dairy products which is essential for nerve health, energy production, bone health and cell repair, research shows levels of this nutrient become lower with age as your body loses its ability to absorb it as effectively¹⁵ Vitamin B12 can also be depleted by drinking alcohol and long term use of some medicines (such as metformin, a common treatment for diabetes) and some antidepressants.¹⁶ As the most potent sources of B12 are from animal sources those following a vegetarian or vegan diet may also be at risk of low levels. Research suggests that an increased percentage of women going through the menopause who are low in vitamin B12 may be at risk of possible psychological changes due to vitamin B12 depletions.¹⁷ These can include fatigue, mood changes, irritability and/or memory problems and confusion or ‘brain fog’, loss of motivation and drive, bladder changes and problems with balance and co-ordination.¹⁸

Folic acid or folate (vitamin B9)

Found in leafy green vegetables like broccoli and cabbage, pulses such as chickpeas or lentils and grains such as quinoa and brown rice. Many studies have found that estrogen therapy - particularly oral contraceptives - can decrease folate levels.¹⁹ Although the research is limited on women taking HRT, further studies have shown that lower levels of folate are responsible for increasing homocysteine levels in women taking hormone replacement therapy and that folic acid has been clinically shown to lower the homocysteine level in postmenopausal woman on HRT.²⁰ An estimated nine-12% of older people in the UK are considered to be deficient in folate – with the most common cause being low dietary intake.² Some people may not have any obvious signs of depletion and may only be picked up only from a blood test but some common signs can include tiredness, memory changes, skin changes and mood changes.²²

Vitamin B6

Also known as Pyridoxine, is found in beef, tuna, salmon, poultry, chickpeas, cereals and vegetables. Estrogen-containing medicines have been shown to cause B6 depletions in some women.²³ Requirements for vitamin B6 increase as we get older as we can have problems absorbing and digesting it effectively.²¹ Lower levels of B6 can lead to mood and sleep changes.

Vitamin C

An antioxidant vitamin found in citrus fruits, peppers and dark green leafy vegetables has been shown to deplete in postmenopausal women taking combined oral HRT.²⁴ Vitamin C is crucial for women during menopause as it plays a vital role in collagen production which helps to maintain healthy skin, joints and connective tissue. Vitamin C is also important for helping the body to utilise the mineral iron (see below). Getting enough vitamin C is also linked to a reduced risk of lowered bone mineral density (the measure of calcium and other vital minerals in your bones).²⁵,²⁶ Figures from 2024 from the National Institute for Health & Care Excellence (NICE) suggest up to 14,000 women in the UK are at risk of fractures following the menopause.²⁷

Zinc

Studies show that oral HRT can increase the body’s requirement for zinc as this mineral directly competes with copper which is known to elevate in women taking HRT.²⁸ A mineral found in shellfish (oysters are particularly high in zinc although few of us eat them on a regular basis); meat; pulses; nuts and seeds; eggs and wholegrains such as quinoa which plays an important role in hormone regulation and immunity. It is also known to help manage mood changes, which are commonly reported during both perimenopause and menopause. Zinc is also key for healthy bone formation, along with key minerals calcium and phosphorous and vitamin D. A study on healthy post-menopausal women has shown that after eight weeks of taking zinc the status of vitamin D in the body improved and that supplementing with zinc can help to maintain bone health during menopause.²⁹

Nutrients that can increase when taking oral HRT

As is the case for both oral HRT and oral hormonal contraceptives Copper has been shown to increase when taking these hormones.³⁰ It is not recommended that you take supplements (either singly or as part of a multi vitamin and mineral) containing copper.

Getting, and maintaining, the nutrients you need

Many of the potential changes in nutritional requirements linked to using oral HRT can be managed by general healthy lifestyle measures including not drinking too much alcohol, not smoking, getting enough sleep, managing stress, taking regular exercise and obviously having a varied and balanced diet. Ensuring you are getting a good level of vitamins and minerals from your food (a Mediterranean-inspired diet should provide you with pretty much what you need) is key. With the best will in the world, however, sometimes we don’t absorb everything we need from diet alone and taking a multivitamin and mineral – specifically one designed for women taking HRT that takes into account how hormone replacement may lead to potential depletions - can fill any small, but sometimes critical, gaps in nutrition. In short, taking a supplement acts as a convenient and effective ‘insurance policy’ to ensure you get what you need nutritionally when using HRT and when you might not be getting everything you need from food alone.