Reference
Supplement and women’s health glossary
This glossary defines the supplement and women’s health terms used across Her Vitals in plain English, from bioavailability and elemental dose to perimenopause, folic acid and EFSA authorised claims. Every definition is written to help you read a label or a guide accurately. It is information, not medical advice, so for your own situation speak to your GP or pharmacist.
B
- Bioavailability Supplement forms
- How much of a nutrient a supplement contains is actually absorbed and used by the body. Two products with the same amount on the label can differ in bioavailability depending on the chemical form, which is why the form of a mineral, not just the milligrams, is worth checking.
C
- Chelated mineral Supplement forms
- A mineral bound to an amino acid, such as magnesium bisglycinate or iron bisglycinate. Chelated forms are commonly chosen for being gentler on the stomach. The label still needs reading for the elemental amount, since that is what your body receives. Magnesium guide.
- CoQ10 (coenzyme Q10) Nutrients
- A compound the body makes naturally that is often added to conception and general wellbeing supplements. It carries no authorised EFSA health claim, so marketing that links CoQ10 to fertility or energy goes beyond what UK rules permit. Discuss any use with your GP or pharmacist.
- Creatine monohydrate Nutrients
- The most studied and usually best-value form of creatine. Creatine carries an authorised EFSA claim that it increases physical performance in successive bursts of short-term, high-intensity exercise, for adults performing high-intensity exercise. It is for adults and is not recommended in pregnancy without medical advice. Creatine for women.
E
- Elemental dose Labels and claims
- The amount of the actual mineral in a serving, as opposed to the weight of the compound it comes in. For example, a magnesium citrate tablet weighs more than the magnesium it delivers. Compare products on their elemental amount, which good labels state clearly.
- EPA and DHA Nutrients
- The two long-chain omega-3 fatty acids that the authorised EFSA claims relate to. EPA and DHA contribute to the normal function of the heart, and DHA contributes to the maintenance of normal brain function and vision. Fish oil is the common source; algae oil is a vegan source. Check the EPA and DHA amounts, not just the total oil weight. Omega-3 guide.
F
- Folate and folic acid Nutrients
- Folate is the B vitamin found in food; folic acid is the manufactured form used in supplements. The NHS recommends a daily 400 microgram folic acid supplement while trying to conceive and until 12 weeks of pregnancy, to help prevent neural tube defects. Some women are advised a higher 5 milligram dose by their GP. Trying to conceive.
H
- HRT (hormone replacement therapy) Women's health
- A prescribed medical treatment that replaces the hormones that fall during perimenopause and menopause. HRT is a clinical decision made with a GP or menopause specialist. Supplements are not a replacement for HRT and cannot legally claim to treat menopause symptoms. Menopause guide.
I
- IU versus micrograms Labels and claims
- Two units used on vitamin labels. For vitamin D, 10 micrograms equals 400 IU, which is the daily amount the NHS advises many UK adults consider in autumn and winter. When comparing products, convert to the same unit so you are comparing like for like. Vitamin D guide.
M
- Menopause Women's health
- The point when periods have stopped for 12 months and the ovaries are no longer releasing eggs. The NHS notes the average age in the UK is around 51, though it varies. Menopause follows perimenopause and leads into the senior years. Menopause guide.
- Micronutrient Nutrients
- A vitamin or mineral the body needs in small amounts, as opposed to the macronutrients (protein, fat and carbohydrate) needed in larger amounts. Most people meet their micronutrient needs from a varied, balanced diet, which is why the NHS treats supplements as a top-up for specific gaps rather than a routine requirement.
- Myo-inositol Nutrients
- A compound sometimes added to conception supplements and marketed around cycle health. It carries no authorised EFSA health claim, so any fertility or hormone-balancing promise goes beyond what UK rules allow. If you are considering it, discuss it with your GP rather than relying on the marketing.
N
- Neural tube defect Women's health
- A group of conditions, such as spina bifida, that can affect a baby’s developing spine and brain very early in pregnancy. Taking folic acid before conception and in early pregnancy helps prevent them, which is why the NHS advises starting folic acid before you conceive. Trying to conceive.
- NRV (Nutrient Reference Value) Labels and claims
- The reference amount of a vitamin or mineral used on UK and EU labels, shown as a percentage next to each nutrient. It replaced the older term RDA. An NRV is a general population reference, not a personal target, so 100 percent of the NRV is not automatically the right amount for you.
P
- Perimenopause Women's health
- The transition leading up to menopause, when the ovaries gradually make less oestrogen and periods become less predictable. The NHS says it often begins in a woman’s 40s, though it can start earlier, and it ends at menopause. Supplements do not treat it and are not a substitute for medical care. Perimenopause guide.
- Postnatal (postpartum) Women's health
- The period after giving birth. The NHS advises continuing a daily 10 microgram vitamin D supplement while breastfeeding. Nutrition in this stage focuses on recovery and, for those breastfeeding, on meeting slightly higher needs from a balanced diet. Postnatal guide.
- Preconception Women's health
- The period while trying to conceive, before pregnancy begins. It is when the NHS folic acid and vitamin D recommendations start, because the neural tube forms in the first few weeks, often before a woman knows she is pregnant. Trying to conceive.
- Probiotic and prebiotic Supplement forms
- A probiotic is a product containing live micro-organisms; a prebiotic is a fibre that feeds the bacteria already in the gut. Under UK rules the word "probiotic" cannot be used to imply a health benefit on a label, so treat gut-health promises with caution and check anything with your pharmacist if you have a health condition.
- Proprietary blend Labels and claims
- A mix of ingredients listed on a label under a single combined weight, without disclosing how much of each nutrient it contains. Blends make it impossible to know whether an active ingredient is present in a meaningful amount, so products that state each nutrient separately are easier to judge.
U
- Upper safe limit Labels and claims
- The highest daily amount of a nutrient considered safe over time, sometimes called the tolerable upper intake level. It matters because more is not better: the NHS warns that high doses of some vitamins and minerals can be harmful, which is why doubling up on products covering the same nutrient is a risk. Do you need a multivitamin.
V
- Vasomotor symptoms Women's health
- The medical term for hot flushes and night sweats, among the most common symptoms of perimenopause and menopause. They are caused by the body’s changing response to falling oestrogen. Persistent or troubling symptoms are worth discussing with a GP. Hot flushes and night sweats.
- Vitamin D3 versus D2 Supplement forms
- The two forms of vitamin D in supplements. D3 (cholecalciferol) is the form usually recommended and is most often from lanolin, though vegan D3 from lichen exists; D2 (ergocalciferol) is a plant-derived alternative. The NHS advises many UK adults consider a daily 10 microgram supplement in autumn and winter. Vitamin D guide.
Z
- Zinc Nutrients
- A mineral with several authorised EFSA claims, including that it contributes to normal fertility and reproduction. It appears in many conception supplements. An authorised nutrient claim is a general statement about the nutrient, not evidence that a specific product improves your chances of conceiving. Best fertility supplements.
Where to go next
Put these terms to use in our evidence-led guides, price a product by its active ingredient with our free supplement tools, or browse everything on the site index. Comparing products? See the best multivitamin for women and the best fertility supplements.
Frequently asked questions
Why do supplement labels use so many technical terms?
Supplements are regulated as food, so what a label can say is tightly controlled. Terms such as elemental dose, NRV and EFSA authorised claim exist so a product describes what it contains accurately without making medical promises it is not allowed to make. Understanding them makes it easier to compare products fairly.
Does an authorised EFSA claim mean a supplement works?
An authorised EFSA claim, such as "vitamin D contributes to the maintenance of normal bones", means that specific nutrient has an accepted role in the body. It does not mean a particular product will have a noticeable effect for you, and it never means a supplement can treat a condition. Supplements cannot legally make treatment claims.
Where can I get personal advice on supplements?
This glossary is information, not medical advice. For advice about your own situation, speak to your GP or pharmacist, or your midwife if you are pregnant or trying to conceive. They can take account of your health, any medication and any conditions you have.
This is information, not medical advice, and is not a substitute for a registered clinician. Always read product labels and speak to your GP or pharmacist before starting a supplement.
Editor, Her Vitals
Oliver leads Her Vitals's editorial coverage of women's life-stage health and supplements. He curates and reviews existing branded products across trying to conceive, pregnancy, postnatal, perimenopause, menopause and the senior years, weighing what the evidence supports against guidance from bodies such as EFSA, the NHS and NICE, and is clear that the content is information rather than medical advice.
Last reviewed: 8 June 2026
Reviewed by Oliver Mackman, Editor. Editorial review against published guidance; not a clinical review.