What dosage of Vit D?: Hello, How much... - British Heart Fou...

British Heart Foundation

40,256 members25,744 posts

What dosage of Vit D?

Lilypocket profile image
20 Replies


How much vitamin D is the optimum dose? I am a female about to be 65 with PAF. My GP gave me a prescription for a glass phial dose of 100.000 u.i a month. It is also for babies ( according to the packaging). I feel it might not be enough. Should I top up? Obviously I' LL check with cardiologist when I see him in March.

Thanks for your replies!

20 Replies
TuckBox2 profile image

I have just finished a course of vit D from my GP 2x 20,000 iu once a week and advised to follow up with 1,000 iu daily. Last week I received the government supply of 3 months of tablets at 400 iu daily.

So I would check with GP for best option

Lilypocket profile image
Lilypocket in reply to TuckBox2

Thanks for your reply! I think actually I'll speak to my gyno/obstetrician because she asked how much I was taking 10 days ago and I mistakenly said 200.000 a month and she said that was good - but in fact it's 100.000.Take care.

With the usual caveat I’m not medically qualified...the short answer is no, that dose is more than sufficient. The longer answer is that age and gender are somewhat irrelevant with vitamin D, and it is one of the few vitamins that you can potentially ‘overdose’ on when supplemented and have medical issues as a result. The general consensus is that the absolute maximum safe, daily dose of vitamin D for those that have been tested and found to be clinically deficient is the equivalent of 4000iu a day, with standard doses for supplementation mostly ranging from 1000 to 4000, and levels should be checked again after about 3 months. For those who aren’t clinically deficient but just need to top up as per NHS recommendations between October and March, the recommended daily dose is only 400iu.

If you divide your 100000iu dose by 30, you get a daily dose equivalent of 3333iu. I was quite severely deficient in vitamin D due to the impact of autoimmune disease and prescribed a supplement of 3200iu a day.

Lilypocket profile image
Lilypocket in reply to

Thank you for your detailed reply. I also was deficient. The dose seems appropriate after what you have said.Take care

A few days ago I received my free Vit D off the Gov!

Contains 1 a day tablet, 400iu

So guess that is what is recommended.

I normally take 1 a day of 1,000iu and I read that it is safe up to 4,000iu (on lit that was with freebies from gov).

Lilypocket profile image
Lilypocket in reply to

Thanks for replying 🙂. I'm in France so although there are many things/tests that are free from the age of 50 (mammograms, colon rectal ) there has been no vit D handout yet. Take care x

MRK-3 profile image
MRK-3 in reply to Lilypocket

I am in France as well, where are you in France Lilypocket?

Lilypocket profile image
Lilypocket in reply to MRK-3

HiI'm in the Paris suburbs and also have a family home near Cherbourg. Where are you? 🙂

MRK-3 profile image
MRK-3 in reply to Lilypocket

I am in the Lot et Garonne nowhere near you unfortunately.

Purplecross profile image

I’m 65 and a take 1,000u x 2 twice a day mine also has calcium in it have to take it for 5 years due to triple break in my wrist and it was found my bones are thinning this what led to open heart surgery to replace valve.Doctors app whilst off with broken wrist led to Bp check. Start of my yourney.

45sue profile image

There is a difference between a therapeutic dose for clinical reasons such as osteoporosis ( for which i am on 1,000 iu per day) for which you should be tested & a supplement - usually around 400 mg

Alison_L profile image
Alison_L in reply to 45sue

Do you mean 400mcg, Sue? I think 400mg would be an overdose :)Last year my GP put me on 1500mcg per week for 10 weeks, then said I should continue with over the counter packs (25mcg/1000IU). I stopped them in the autumn as they were making me feel bloated, but when I had my bloods done in December, my vitD level was fine.

45sue profile image
45sue in reply to Alison_L

Yes- I must mean 400mcg. I get mixed up with all these different units. If Vit D deficiency is suspected, the main point is to have the levels checked by blood test before deciding on what is best dose

ILowe profile image

I found a nice little calculator here, which takes into account your weight, and if you know your blood level or not. There are good reasons to start with a loading dose, then slow it down to a regular smaller dose. grassrootshealth.net/projec...

Lilypocket profile image
Lilypocket in reply to ILowe

Thanks! X

in reply to Lilypocket

I would be extremely cautious of this calculator - I just put in my details and it advised me to take 9000iu, which is more than twice the medically accepted safe maximum daily dose of vitamin D. For a loading dose it was suggesting I take 25,000iu A DAY for 10 days, which is 6 times the upper safe limit. Medical problems have been recorded in people taking 10000iu a day for several days.

Mrverycross profile image

Gosh, NHS website, and what I've read/heard elsewhere, states 10micrograms per day which is 400iu I believe for normal adult requirements. Most UK adults are somrwhat deficient in vit d I guess due to latitude with poc even more so.

Lilypocket profile image
Lilypocket in reply to Mrverycross

Thanks for replying ☺️

ILowe profile image
ILowe in reply to Mrverycross

nhs.uk/conditions/vitamins-... True, they recommend 400iu, but scroll down, they also say that up to 4000iu is the limit.

Raft profile image

I get very confused with the different ways of measuring Vit D and other supplements and what seems a very wide range of treatment levels. Where can I find the most reliable information on this and other supplements please?

You may also like...