Vitamin D. How much is enough?

Vitamin D, how much is enough?

I love when GPs finally get what prevention is and we agree on things. I have been trying to get them to see that my vitamin D had not been enough and because in my family who live in Italy with plenty of sun, there seem to be a problem converted the vitamin D in the kidney, I had to insist to have my density scan. Now the same doctor kept saying that my vitamin D was in the normal range, which it is, however for me was still low 50 to 76 it went down instead of up. I have been taking vitamin D during the winter, the good one and been in Italy. So I would have thought that should go up and be better. However maybe there is something to do with my liver, which I have a weakness with, if the fat is not broken down properly, or the bile does not work well enough, then it is possible that vitamin D is not absorbed well enough. Hence I have a bit of osteopenia, which of course the doctor will not treat till it becomes bad. As a nutritionist and a therapist I rather do the prevention. So finally I got a doctor that saw that vitamin D can be put up to 170 with a 20.000 iu for 12 weeks (yes I could have taken that by myself, however even as a nutritionist I would have wanted a bit more information regarding my bone state. So now that I know that my bones were a bit depleted, I am taking the vitamin D at higher dosage as well as extra calcium, and then in a year time I will double check my bones again to see how it worked.

How much is vitamin D for you. Well if you had a multiple pregnancy and breastfeeding, I would suggest to take up to 5000 iu in drops during the winter and less during the summer if you are young. If you are older or had the above situation, or you have been inside for a long time, had any fractures, the,  I would suggest to check your vitamin D. Just ask your doctor, and if it is about 76, then I would take enough vitamin D such as 5000 iu in drops for at least 12 to 16 weeks. If you are older, find a doctor that would give you very high dosage of vitamin D to bring it to at least above 100nmol/L.

Vitamin D is not only important for your bones. It is important for many other functions, including blood clotting. Hence if you do have a blood clotting problem, or taking any warfarin or any other medication for blood clotting, consult your GP before taking extra vitamin D.

One of the study that I read, also showed that having an optimum vitamin D can also reduce liver steatosis (non-alcoholic fatty liver) after only 4 weeks. More about this in my next nutrinews.

Many research have shown that, there is no much toxicity with taking high amount of vitamin D, as the body will just switch off the conversion of the vitamin D in the hormonal form. In order to be on the cautious side though, there is a suggestion to stay within the 250 nmol/L in the blood as the upper limit, however there is only a bit of hypercalcemia above 750 nmol/L. Therefore 20.000iu for 12 weeks and more if you have osteopenia might be good (this needs to be suggested by the doctor though).

If you are 70 nmol/L and below, and the GP does not suggest taking extra D, I would take the 5000iu if it is possible for you for the beginning of the Winter in September till next May, especially if you are above 40.Remember that prevention is better than cure, once the bone density is reduced and you are much older, it is more difficult to improve it. Do start early rather than later.

This is what I wrote about the function of vitamin D and osteoporosis a while back:

Building strong bones for prevention of osteoporosis even at young age

Autumn is almost here and with autumn in England the sun ray will be a bit further away, which it means less vitamin D forming for all of us.  All the seasons are wonderful as each brings their own beauty and health. Even though we might eat as healthy as possible though, vitamin D is one of the vitamins that we might all lack at the end of winter if we do not supply ourselves and our children extra in a supplement form. Since the testing of vitamin D around the world, there is an increase awareness of how little vitamin D we get from our food and light in England and countries where the Sunshine is little and short in supply. Most of our vitamin D comes from the sunshine, however I have seen and experienced low vitamin D even in the sunniest countries. That is because vitamin D needs to be activated by the liver and kidneys and if that they do not work properly either genetically or for overload, then we end up with very low bioavailable vitamin D. My suggestion as a Nutritionist is to supply the vitamin D3 from November to April and spend as much time in the sun or outside as possible to get some from the skin. If you are one of the lucky ones that can go away for the winter, then you do not need as much. Darker skins do need more exposure or take the extra supplement as the light in England will not be enough. You can get some vitamin D from oily fish and from dairy and eggs however might not be enough or if you have problems with your intestinal tract and digestion you might not absorb it enough and especially if you are intolerant or allergic to diary and you do not know or you keep having it.

Vitamin D is not the only minerals important for the bones. The obvious other ones are calcium and magnesium, however zinc, boron and K2 (vitamin K2 and in some extend K1 prat of vitamin K family) are also essential for bone health. Phosphorus as important as calcium, about 80% of phosphorus is found in the skeleton, 14% is found in muscles and body tissue and the remaining is found in body fluids and blood.

  • Phosphorousis found in a lot of foods including meat, fish, eggs, milk, nuts cereals, grains chocolate. Unfortunately, a lot of the junk foods and drinks also contain a lot of phosphorus and quite often if you have not a good diet with plenty of calcium to balance that out, you might end up with too much phosphorous and little calcium If you eat healthy, than phosphorus is found in meat and dairy and vegetables.
  • Zincis found in pumpkin seeds, oysters and meat;
  • Boronis found in fruits, vegetables and legumes, and not so much in meat and fish.
  • Vitamin Kis found mainly in green leafy vegetables, highest in the endive lettuce and dark green vegetables,

Exercise also is very important for inserting calcium and other minerals into the bones. This is done by getting the old bones out and renewing the bones with the new minerals.

As little as walking at a fast pace is enough to get the calcium in. Any other weight bearing exercise is also great. Swimming is not useful for building bones, but great for keeping fit.


  1. Arai H. and Sakuma M. (2015). Bone and Nutrition. Bone and phosphorus intake.Clin Calcium. 25(7):967-72. (abstract)
  2. Gennari C (2001). Calcium and vitamin D nutrition and bone disease of the elderly. Public Health Nutr. Apr;4(2B):547-59.
  3. Groff J. L. & Gropper S. S. (1999) 3rd ed. Advanced Nutrition and Human Metabolism.UK Wadsworth.
  4. Jones G. (2008). Pharmacokinetics of vitamin D toxicity. Am J Clin Nutr. Aug;88(2):582S-586S
  1. Papapostoli L. et al (2016). Effect of Short-Term Vitamin D Correction on Hepatic Steatosis as Quantified by Controlled Attenuation Parameter (CAP). J Gastrointestin Liver Dis. 25(2):175-81
  1. Uenishi K. (2015). Bone and Nutrition. Calcium intake and bone health. Clin Calcium.25(7):959-66.

Leave a Reply