Thyroid UK
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Are my iron/b12/folate/ferritin ok?


On the advice of some very helpful people on here I got a print out of my results. Doc doesn't think I need supplements other than the vit D she gave. The results are within range, but I've read on here that they should be higher than they are for Levothyroxine to work effectively. I'm now on 50 mcg (was diagnosed at the end of Dec). Would anyone be able to advise please?

Tsh 6.3 (0.27 - 4.20 )

Free T4 14 (12-22)

Serum folate 6.43 (4.60-18.70)

B12 397ng/L (191.00 - 663.00)

Serum ferritin 27ug/L (13.00- 150.00)

Iron- serum iron 10.7 (7.00-26.00)

Saturation iron binding 63.oo (45.00-70.00)

Percentage iron saturation 17% (20.00-50.00%)!

(Doc said this is ok because my haemoglobin is 135gl (115.00-165.00 ))

I'm barely functioning at the moment, just managing to eat and wash (!), read a little and walk very short distances (50 yards). It's a struggle to do simple tasks. I'd really appreciate any help. (With interpreting the blood test, not my chores ha ha! Though that would be good.....!) I've got a lot of aches, pins and needles, fuzziness and heaviness and don't feel much better since starting the medication.


6 Replies

Jeanlouise, you're feeling rough because your TSH is high and your FT4 low. Book a repeat thyroid blood test 6-8 weeks after you were increased to 50mcg and don't take your Levothyroxine for 24 hours prior to the blood test. Most people feel comfortable with TSH just above or below 1.0 and FT4 towards or in the top 75% of range. It can take a couple of months after biochemistry is good before symptoms finally resolve.

NHS won't prescribe when vits/mins are within range but you can buy supplements to improve yours. If you use Amazon please use the TUK/Amazon affiliate link

B12 <500 can cause neurological symptoms and most here supplement to get B12 to the top of the range. 1,000mcg methylcobalamin sublingual lozenges, spray or patches should be enough taken with a B Complex vitamin to improve your folate and keep the other B vits balanced.

Ferritin is optimal halfway through range so supplement Ferrous Fumarate and take each iron tablet with 500mg-1,000mg vitamin C to aid absorption and mitigate constipation. Retest after 5-6 months and stop supplementing 2 weeks before you test.


Whilst it's common for people with hypothyroidism to be low in vitamins & minerals whilst treatment is being put in place to correct the thyroid hormone balance I personally would be a little cautious about supplementing with vitamins B12 . This because some people also develop Pernicious Anaemia,along side hypothyroidism. Taking vit B12 will mask these symptoms & once taken any repeat tests of B12 means u have to stop Taking b12 for at least 6-8 weeks. You could ask you GP to test you for intrinsic factor -often absent in PA. You might want to look at the Pernicious Anemia website and they are also on health unlock & am sure will give you good advice on how to get this checked out to rule out. Then supplement away!!!


You really need to get your iron levels up and quickly. Your ferritin should be at least 70 for you to be able to convert the T4 you're taking to usable T3. Low iron could in itself be the cause of many of your symptoms too. Your other iron tests don't look great either despite what your Dr says. Hemoglobin is the last place anemia shows up! My ferritin was 18 in Oct (in range) I've been taking Spa Tone since then, but it really hasn't done anything, in fact I got worse! I had private FT4 and FT3 done which showed FT4 mid range and FT3 bottom of the range. This proved to me that I wasn't converting well. After a bit of googling, iron seemed to be the main culprit. I went to the Dr a week ago. Coincidentally, my symptoms peeked that day. I was feeling dizzy and my heart was racing, but because my temp was 37.3 he said I had a virus!!! I also got AF that day which confirmed the iron def to me. Anyway, he prescribed Ferrous Sulphate 200mg 3 x a day. Although I'm not 100%, I managed a 21/2 mile run today which I've not managed in about a month. You don't need a prescription for the iron, in fact its cheaper without.

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A lot of people find ferrous sulphate to be very hard on the gut. It is very irritant. An alternative is 210mg ferrous fumarate which can be bought in boxes of 84 from most pharmacies (not Boots). This is enough for 3 per day for 28 days. The last box I bought cost £4.14 from Tesco Pharmacy.


Hello Janelouise, I agree with the other posts re. Iron. I had similar readings for Serum Ferritin, which is the store of Iron in the body. Despite telling my GP I thought I was anemic he insisted I wasn't. So it went untreated for years, and led to a host of other problems. Eventually I had to change GP thankfully he was excellent but alas soon left. He prescribed Ferrous Sulphate, but it took about 2 years of 3 tablets daily to get my stores up and for me to feel a bit better. However, treating the damage, left in the wake of the first GP's incompetence, remains ongoing, over 10 years on. I can't recommend what to do, but low iron stores can cause absolute havoc, so its important to get treated. However, it needs to be taken in context i.e personal history, symptoms, other conditions, etc. Perhaps you could see another GP who will look at the bigger picture as mine did and give you a treatment plan. I don't think self medicating is wise but may be necessary if all else fails. Best of luck.

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Thanks so much for all the advice, I'm going to ask for a referral and now know the type of questions to be asking and what to look for. I'm having more detailed blood tests next week too.


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