Brief Answer:
probably MCV is raised secondary to alcohol abuse.

Detailed Answer:
Hi and Welcome to "Ask A Doctor" service.
I have read your question and here is my advice.

Little variation of indices of RBC do occur.
This is mostly not worrisome if your haemoglobin, white cell count and platelets count are not grossly abnormal. Regarding your labs let me explain it.

The lower normal ferritin and low mchc probably mean little deficiency of iron, though we always see the other result like your haemoglobin level. So the nurse probably thought like this. Low mchc may indicate iron deficiencies though not always but in otherwise healthy people we recommend iron and to follow the test in little time. But this does not means necessarily low iron( as ferritin is normal and much is not too low,) but taking it is not a bad idea especially if haemoglobin is little low.

However high MCV does not occur in iron deficiency rather the MCV gets low in iron deficiency .your GP is right, this is unlikely if you are not anaemic (low haemoglobin). Causes of high MCV are many like bit b12 and folate deficiencies thyroid disease and few more. Yes, chronic alcohol abuse is one cause of high MCV. And in your case, as folate and b12 are normal this is probably the chronic alcohol use that has caused your MCV to rise. This does not necessarily means something irreversible but indicates that there are some toxic effects of alcohol on bone marrow. The toxic effect of alcohol on bone marrow causes high MCV. This is reversible, And generally, in about 2 months time, the MCV becomes normal If alcohol is stopped. I am afraid you are taking a little higher amount of alcohol, 20 units are clearly over the safe range for a female. So I would advise to try your best to avoid alcohol or cut it to the minimum possible amount, this high MCV cannot predict other effects of alcohol on the body like liver, brain, and almost every part.
So personally I understand nothing sound too bad, cut on your alcohol, take some multivitamins and iron tablets (not necessary but better to take) and repeat the test in about 2 months. I would also recommend doing liver tests to see if alcohol has any effect there.

Hope this answer helps you understand your query.
Let me know if you have any further questions about it.

Regards
Dr Mahboob ur Rahman

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Brief Answer:
Not an emergency, you can do the liver tests latter any time.

Detailed Answer:
Hi, thanks for your compliments,
It's so good to hear that you are aware of the hazards and you take good care of your health.
Infact this is a wake up call, but don't worry, nothing sounds serious. These changes will reverse in inittle time.
You need not to worry too much. Most people don't get any liver disease with alcohal but still wee need to consider it(it's the commonest cause of liver diseases in the west) and try to avoid it(or reduce it to a minimum level). Checking your liver functions is not an emergency in such cases you can do it latter when ever you get a chance.
However few things I would like to share are ;
1. That normal liver functions do not mean that alcohal would not cause any damage to the liver so abstinence is the best idea every time.
2. Though the damage that alcohal can do is proportional to the amount one take it, and their was a concept of safe level (14 units a week for female), but latest multinational study reveled that no level of alcohal can be guaranteed to be safe. (though most people who use it don't get any problem but every one is at risk)
So I just want you should focus on reducing the level to the most, best to quit it. I understand this is not an easy thing, but you should try to make it the minimum.

At this moment nothing sound very bad, keep enjoying.
Wish you best health.
Please dont hesistate to ask if you have any further query. I would be glad to answer.

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