So, this thread will possibly end up being a little personal if others respond to it. I don't mind that - there are so many conflicting anecdotes about what to expect, as a woman at different stages of life, when going vegan. It occurred to me that since it is also quite an emotional topic we should have a support thread here for it.

I'll break the ice. I have been vegan for almost two years (come April) and lacto-vegetarian for many years before. When I had cut out all animal products bar dairy and honey, as a lacto-vegetarian, I did not notice any change in my hormones. I suspect that the chief culprit would have been the dairy. However, when I reduced this and went vegan, it was all-change.

Some women have reported losing their periods since going vegan yet retaining their fertility. I know that many women do not like having periods but I can't help but think that, at the end of the day, most would not want to lose it altogether and I do have my concerns about the vegan women who say that they are still OK. How do they know? Did they have their AMH levels checked?

A common report is that periods become lighter or less voluminous for vegan women. This makes sense to me; the blood, for instance, is clearer. It's not that the cheese gets redirected into the uterus, obviously!, it's that eating animal products generally leads to more secretions of cervical mucus (and other mucus secretions around the body) that - in turn - mixes in with the lining. Clots, though common, are not a sign of good menstrual health. Thicker periods can also be caused by a prostaglandin imbalance, in turn caused by oestrogen-dominance. Again, the causal link between dairy and oestrogen is well documented.

It can also be caused by vitamin A and C deficiencies - conditions that vegans rarely suffer from because the best sources of vitamin A and C are plant-based. Indeed excessive amounts of vitamin C can lead to recurring mouth ulcers (many don't know that you can actually have too much vitamin C if you're not eating a varied diet to compensate). For vegans, however, there is the issue of getting in your B12 and folic acid, which both affect iron absorption and, therefore, affect what your period will be like.

Speaking to other vegan and non-vegan women about menstruation, some have been disturbed by the thinner periods they were having - as if thicker ones somehow resembled a 'strength' of the lining. Facts are, however, that extra mucus does not make the uterine lining any stronger. If anything, excessive mucus can lead to more complications. We can also be comforted that there have been generations of healthy vegan babies being born now, and that these pregnancies and births are well documented.

The difficulty, perhaps, will be in assessing the change in the volume of blood once most of the mucus is taken away. A little mucus is good - particularly at the time of ovulation - but too much is not. Bright red is a good colour too - it means that the journey from shedding is a quick one. Darker colours mean that the blood is not coming out in timely fashion, or that you are not changing your tampon often enough. (Not doing so can be serious: it can even cause blood poisoning.)

There is also the matter of weight loss. If you go vegan, there is a good chance you might lose a little bit of weight. It is important to keep tabs on your body-fat percentage as well as your BMI. Losing weight will upset your hormonal balance until it stabilises again. Therefore my advice to new vegans would be to reserve judgement on any period change they notice until after a few cycles and they feel settled into their new diet.

On the matter of phyto-oestrogens (plant based oestrogens such as soy) there is a matter of debate. Older studies seemed to think that eating soy could help (or create) hormonal imbalances, whereas newer studies suggest that phyto-oestrogens cannot be converted into mammalian oestrogens and therefore soy should not be a concern. If you are further interested, I encourage you to do your own research.

But any change can be unsettling: whether you are just starting to have periods, they have changed, whether you are trying to conceive, are pregnant, post-pregnancy, or whether you are coming up to, experiencing, or are beyond the 'second change of life'.

If, however, you are still concerned that your period has become too thin, watery, or that it has been lost there are some explanations or remedies you can consider. Failing these for a few cycles, please consult your doctor and do not wait any longer. So, in no particular order:

1. You might be underweight, or your body fat percentage might be too low. You need to rule out this possibility - this website can help you http://www.bmi-calculator.net/
2. Of course, the change might be due to pregnancy. You will need to test and make sure. Vegan pregnancy diets do require planning - there is further information on the UK Vegan Society's website.
3. You might just be stressed. Consider ways to reduce your stress and address your sleep pattern if this is irregular. Plenty of suggestions for stress and sleep elsewhere online.
4. If you are a raw food vegan, or fruitarian, you might not be getting enough fats into your diet. A little fat is good. Consider avocado, coconut, olives, and other nuts and seeds if you can. Omega oils are needed as well.
5. A B12 deficiency is one of the major causes of light or no periods in vegans. Please consider supplementing or buying fortified foods. Please note that the body does not absorb B12 particularly well - you should be absorbing at least 4 µg every day and the method of taking the B12 will affect the absorption efficiency. If you find a source that you can absorb well, you should notice a difference within your next full cycle or two.
6. Are you using a hormone-based birth control method? To assess whether your vegan diet is affecting your menstruation, you might consider coming off your hormone-based contraception for a while. There are certified-vegan contraceptive methods out there (mostly condoms).
7. If you are unsure whether you are getting all your dietary needs in vitamins and minerals you might consider tracking your daily consumption on a macro-counting site like Cronometer (which is free).
8. Do you have another illness which might be affecting your period? Have you been checked for PCOS? A quick ultrasound of your ovaries should tell you all you need to know, but the process is a little invasive (the ultrasound device needs to go up your uterus, a nurse will do this).
9. Are you restricting your calories? Please do not attempt to force your body into drastic calorie-deficits which can affect its ability to take care of your uterus. Do you suffer from an eating disorder?
10. Is it possible you have a thyroid problem? This can be established with a blood test.
11. Please consider the other deficiencies mentioned in this post, particularly iron. In order to isolate your deficiency I do not recommend - for instance - taking a 'complex' tablet. Instead, take the individual supplements and cut one out at a time to try to establish which lack might be the culprit.
12. Consider herbal remedies for overly thin or absent periods. More information can be found online. These can be very effective so you must be careful if you are taking other medications with which they might interfere.

Please note that I am not a doctor or trained professional.
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