ferritin 16 range 15 - 150
folate 2.2 range 2.5 - 19.5
vitamin b12 207 range 180 - 900
total oh vitamin d 13.5 range <25 severe vitamin d deficiency patient may need pharmacological preparations
Regarding the folate and vitamin B12 levels, you need to ask the people with Pernicious Anaemia (PA) for help, because they know lots about B12 and folate deficiency. They have a forum on HU which can be found here :
You will have to follow the PA Society just like you followed this one. The follow option is in the banner at the top of the page at the link I just gave.
Ferritin : Your ferritin (iron stores) is much too low. In order to make good use of the thyroid hormones you take your body needs good levels of minerals and vitamins. For ferritin this means having a minimum level of 70. Optimal would be mid-range or a little bit higher. So with the reference range you give a level of about 80 - 100 would be good. Some people need it to be a little higher - say, 100 - 120. Don't go to the top of the range.
In an ideal world you would check some other levels before starting iron supplementing. A full iron panel can be done with a finger-prick test with Medichecks :
But I think in the short term your ferritin is so low that supplementing shouldn't do any harm.
it is essential for anyone taking iron to get tested regularly - how often this is depends on how quickly your levels rise. I would suggest testing after 2 - 3 months to begin with. If your levels rise slowly you could test rather less often - say every 4 months.
With all iron supplements the important thing is to know how much elemental (pure) iron there is in the supplement.
Ferrous fumarate 210mg (FF210) is a popular supplement. Doctors prescribe it but it can be bought in pharmacies (if the pharmacist agrees) and online without a prescription. I managed to get this (in a box of 84) from Lloyds and Tesco pharmacies without any bother. Boots are less obliging. Each pill of FF210 contains 69mg of pure iron. The normal dose is 1 tablet, 3 times a day, giving you 207mg pure iron per day. The ones I bought looked like this, but there are other brands :
Ferrous sulfate (sulphate) 200mg - similar levels of pure iron to FF.
Ferrous gluconate - contains roughly half the pure iron of FF.
Ferrous (or iron) bisglycinate - contains about 20mg - 25mg pure iron, depending on brand. Sometimes sold with the name "Gentle Iron".
Alternatives are haem (UK spelling) or heme (US spelling) supplements, or supplements that contain ferritin directly rather than iron. I've never tried either of these and they are more expensive that the supplements I listed above. For more info, see this written by one of the admins here :
Another alternative is to eat a good-sized portion of liver (any kind) or black pudding a couple of times a week, if you eat meat.
Whichever form of iron you take you need to take 500mg - 1000mg vitamin C per dose of iron. This has two advantages.
1) It helps the body to absorb iron.
2) Some people suffer from constipation when they supplement iron. Vitamin C has the opposite effect. Adjust the Vitamin C dose to keep yourself comfortable.