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Pregnant. Have kidney stone. Getting constipated after taking materna. Suggest safe medicine

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Practicing since : 1999
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Hi Dr. Raichle,

I wanted to ask you a question on vitamins. I just had my annual check up with the urologist yesterday and my kidney stone has grown from 3mm to 9mm this year. I was very concerned. One of the things that likely contributed to that is that my multivitamins have 600mg calcium from carbonate. I am trying to find multivitamins now with low calcium and also chelated iron or no iron (so I can take iron separately), since the other iron gives me constipation. So there are some vitamins like that out there but some of the other ingredients in them are quite high (mainly B vitamins or vitamin K). So is it safe to take a vitamin with the following ingredients:

1. Up to 80 mcg of vitamin K - I know vitamin K is not good in large doses so I am not sure if up to 80mcg is ok in prenatals
2. Up to 800mcg of biotin - it seems that in large doses it's not safe and materna only has 30mcg. But a lot of the vitamins I am looking for (low calcium, chelated iron), have from 300 to 800mcg of biotin. Is that too much and is it safe in pregnancy/breeastfeeding?
3. Up to 30mg of B1 and B2 - materna has about 2mg each. Are such high doses ok for pregnant and breastfeeding women?
4. 50mg of B6. Again, this is consistent with B-complex vitamin but Materna only has about 2mg. The prenatal vitamins I found start from 20mg of B6 and go up to 50mg and more, is that safe in pregnancy or breastfeeding?
5. Up to 50mcg of B12 when Materna has about 3mcg?

I wish I could take Materna but I can't because of the iron that constipates me. So far, I had some really good vitamins similar to materna, but the calcium was 600mg and my kidney stone went up through the roof. Before my pregnancy my kidney stone was stable for 4 years at 3mm. So I am quite lost right now since the vitamins I am finding (mostly organic and highly recommended online) seem to have such high doses of the vitamins B or K and I am not sure anymore if they are safe for pregnancy and breastfeeding. If they are labeled prenatal, they should be safe, but again, when I read recommended doses online, they dont seem safe. But I dont have much of a choice at this point, other than stop vitamins all together, which cannot be good either. So I was wondering, from your experience, have you prescribed vitamins with the doses of B and K I have listed above, and is it safe after all?
Thanks so much for your help!
Posted Fri, 10 May 2013 in Pregnancy
Answered by Dr. Timothy Raichle 6 hours later
Hello, I would be happy to help you with your questions - thank you for the direct question! I have found some information on the usual daily intake of the vitamins that you mentioned. I would caution you, though, to avoid high doses of vitamins that exceed the recommended daily doses. For example, Vitamin A in high doses is HIGHLY teratogenic and associated with multiple birth defects. So in these alternative vitamins, the high doses of other vitamins are possibly harmful and in many cases, the chance of harm is completely unknown - as you have found out. Here are the recommended daily amounts for the ones you mentioned:

1. Vitamin K – daily intake of up to 90 mcg/day is considered normal
2. Biotin – daily intake of up to 30mcg / day is considered normal. Doses of 800 mcg would be excessive and there is no evidence of whether or not this causes harm in pregnancy or breast-feeding, but I would not take a vitamin that has these doses.
3. Vitamin B1 / B2 – normal daily intake = 1.4 mg during pregnancy and breast feeding
4. Vitamin B6 – normal daily intake = 1.9 mg during pregnancy and breastfeeding – this is often used in hire doses during the first trimester for nausea and vomiting, so the larger doses in this case are considered
5. Vitamin B12 – normal daily intake = 2.6-2.8 mcg during pregnancy and breastfeeding

As far as the kidney stone issue, there is certainly evidence that restricting calcium intake might be beneficial, but you need the extra calcium during the pregnancy for yourself and the developing fetus. Even though the stone has increased in size, it is probably big enough that it poses little chance of causing a problem during the pregnancy. You will need this dealt with when you are not pregnant. You should ask the Urologist if they are concerned with it during a pregnnacy and at what point they would recommend treatment.

Here is a 'copy and paste' from a source regarding stones and home treatment. I am sorry about the length, but you obviously do a lot of reading about facts. I hope that it is helpful in some way:

Dietary modification — From the viewpoint of diet, increasing the intake of fluid, dietary calcium, potassium and phytate and decreasing the intake of oxalate, animal protein, sucrose, fructose, sodium, supplemental calcium and supplemental vitamin C may be beneficial. The role of vitamin D in stone formation remains unclear.

The importance of a possible "stone clinic" effect following dietary recommendations should not be underestimated. One study found that 58 percent of 108 patients evaluated for kidney stones had, over a five year period, no evidence of active stone disease after a visit to the stone clinic in which minimal advice was given regarding diet and fluid intake. Those patients who did not form new stones showed an increase in urine volume at follow-up versus no change in those who continued to form stones.

Increase fluid intake — Increasing fluid intake, spread throughout the day (although it is not essential that the patient wake up several times per night to urinate), will increase the urine flow rate and lower the urine solute concentration, both of which protect against stone formation. In one prospective trial, 199 patients with a first calcium oxalate stone were randomly assigned to no therapy or recommendation of a high fluid intake to produce at least 2 liters of urine per day. At five years, the incidence of new stone formation was significantly lower in the treated patients than in those in the control group (12 versus 27 percent).

Similar findings were noted in another prospective study. Stone formers who remained free of stones were noted to have a greater increase in urine volume than those who had recurrent disease (320 mL/day versus no change). This study emphasizes that even small increases in fluid intake can reduce the risk of new stone formation.

■Type of fluid — The risk of stone formation might be affected by the type of beverage consumed.

•Grapefruit juice may be associated with an increased risk of stones, although a potential mechanism has not been identified. Although data are limited, avoidance of grapefruit and grapefruit juice may be reasonable in patients with calcium oxalate stones.

•Coffee, tea, and alcohol have been reported in prospective observational studies to be associated with a lower risk of stones. Thus, there is no evidence that these beverages should be avoided to prevent stone formation.

•Cranberry juice, advocated as prophylaxis against recurrent urinary tract infections, increased the urinary saturation of calcium oxalate when ingested in large amounts (one liter per day). Ingestion of moderate amounts is unlikely to be harmful, and there is no evidence that this beverage is beneficial for stone prevention.

•Results from one randomized trial suggest that reducing soft drink consumption may reduce the risk of stone recurrence, although it is unclear what fluid replaced the soft drink. We suggest that patients avoid calorie containing beverages, such as sweetened soda, to avoid weight gain with the general increase in fluid intake.

Reduce animal protein intake — Adverse changes in urinary calcium and citrate excretion can be induced by a high protein diet, since the metabolism of sulfur-containing amino acids increases the daily acid load by generating sulfuric acid. Animal protein is much more likely to induce this effect than vegetable protein, since it has a higher sulfur content and therefore generates more acid.

Thus, lowering animal protein intake will produce favorable changes in the urine. However, it has not been proven that this will reduce the incidence of stone formation. In observational studies, a high animal protein diet was a risk factor for renal stones in men, but not in women. In a randomized trial, reduced animal protein in association with higher dietary calcium and lower dietary sodium was associated with a reduced risk of stone recurrence, but the individual impact of animal protein could not be determined. Based on the available data, it would be prudent to avoid excessive animal protein intake.

Increase fruit and vegetable intake — Foods that are XXXXXXX in potassium, particularly fruits and vegetables, may be beneficial. Increasing intake of fruits and vegetables may reduce the risk of calcium oxalate stone formation, particularly in patients who self-select a diet that is low in fruits and vegetables. This benefit is primarily the result of increasing citrate excretion.

Limit dietary oxalate intake — Some foods contain very large amounts of oxalate and those should be avoided (eg spinach, rhubarb). In addition, some nuts and legumes are also high in oxalate and the intake should be limited (eg, peanuts, cashews, and almonds). The oxalate content of foods is available at the following website: WWW.WWWW.WW
However, there is scant evidence that low oxalate diets reduce the risk of stone formation. In prospective observational studies of individuals who had never had a stone, higher dietary oxalate only slightly increased the risk of incident stone formation in men and older women; there was no association in younger women. Because of the documented health benefits of many foods that are traditionally considered high in oxalate (but still 10 mg or less per serving), strict oxalate restriction does not seem to be supported. As noted above, some foods traditionally believed to be high in oxalate, such as tea, do not increase the risk of stone formation. If a low oxalate diet is recommended, it should only be continued if there is documented evidence that the urine oxalate excretion has fallen.

Limit sodium intake — Calcium is reabsorbed passively in the proximal tubule down the favorable concentration gradient created by the reabsorption of sodium and water.

Thus, a low sodium diet (to 80 to 100 meq/day) can enhance proximal sodium and calcium reabsorption, leading to a reduction in calcium excretion. In one study, for example, lowering sodium intake from 200 to 80 meq/day diminished calcium excretion by as much as 100 mg/day (2.5 mmol/day). Although the independent contribution of lowering dietary sodium intake on actual stone formation is unknown and higher sodium intake may be associated with higher urine volume, it is likely an important component of a regimen that has been demonstrated to reduce recurrent stone formation.

Limit sucrose and fructose intake — Sucrose intake increases urine calcium independent of calcium intake and has been associated with an increased risk of stones. Fructose intake also is associated with an increased risk of stone formation.

Calcium intake — Higher urine calcium is a common finding in stone formers, but restricting dietary calcium intake is not recommended unless it is excessive (more than 2000 mg/d). Although urine calcium excretion may decrease with restriction, the decrease in free intestinal calcium can lead to increased absorption of dietary oxalate and enhanced oxalate excretion, due to decreased binding of oxalate by calcium in the intestinal lumen. The net effect may be increased supersaturation of the urine with respect to calcium oxalate and an enhanced tendency to stone formation.

The ability to help prevent new stone formation with a normal calcium intake was shown in part by a five year study that compared two diets among men with idiopathic hypercalciuria and recurrent calcium oxalate stones. In this trial, 120 such men were randomly assigned to either a diet consisting of a normal amount of calcium (1200 mg/day [30 mmol/day]) and low amounts of animal protein (52 g/day) and salt (2900 mg/day [50 mmol/day] of sodium chloride) or a diet containing a low amount of calcium (400 mg/day [10 mmol/day]).

At five years, a significantly lower risk of stone recurrence was observed among the group assigned to the normal calcium, low animal-protein, low-salt diet (unadjusted relative risk of 0.49 with a CI of 0.24 to 0.98). This selective benefit likely arose because of a decrease in urinary oxalate excretion compared to an increase with the low calcium diet; the urine calcium actually decreased in both treatment arms. However, the independent effect of calcium is unclear given that the amounts of animal protein and salt ingested among those in the low calcium diet differed from that of patients in the normal calcium diet group. Nonetheless, the low calcium intervention was not beneficial and is not recommended.

In addition to increasing stone formation, a low calcium diet may have a second deleterious effect in patients with idiopathic hypercalciuria: development of negative calcium balance. This extra loss of calcium can exacerbate the already diminished bone density in some of these patients, a complication that may be due to enhanced bone resorption.

It should be noted that calcium supplements do not appear to be effective in preventing recurrent stones and may even slightly increase risk.

Other factors — High dose vitamin C appears to increase urine oxalate excretion in certain individuals and the risk of stone formation; thus, high dose supplements should be avoided in those with higher urine oxalate excretion. Phytate appears to decrease the risk of stones in women. Although not simply a matter of dietary intake, higher body mass index increases the risk of stone formation, particularly in women. Therefore, weight control may be helpful in preventing stone recurrence

I would schedule a visit to further discuss all of this with your Urologist and your OB/GYN. Good luck!!
Above answer was peer-reviewed by
Follow-up: Pregnant. Have kidney stone. Getting constipated after taking materna. Suggest safe medicine 11 minutes later
Thanks Dr. Raichle for the detailed information. There is no response that is too long:)

So unfortunately the best vitamin I found has 25mg of B6 and 300mcg of biotin. So that is about 10 times higher than the doses you list above. This vitamin is called VitaMed MD Plus prenatal and has non-constipating iron and low calcium (only 150mg). I thought this might be a good option for me but seems like it's not. Would you be able to then recommend me a specific vitamin that is low in calcium/or no calcium? I would drink 4 glasses of milk a day to get my calcium, I would make sure of that. Also, this vitamin has to have non-constipating iron i.e. chelate or no iron at all (I can take it separately) or other type of iron, but not ferrous fumarate. Would you know of such vitamin?
Thanks so much!
Answered by Dr. Timothy Raichle 1 hour later
Just to clarify- how pregnant are you and do you eat a regular diet?
Above answer was peer-reviewed by
Follow-up: Pregnant. Have kidney stone. Getting constipated after taking materna. Suggest safe medicine 21 minutes later
I am 34 weeks pregnant, just finished them and today is day 1 of week 35. Unfortunately my diet is a bit restricted because of the kidney stone, I read your article and also my urologist gave me some brochures too. I try and eat 3-4 cups of veggies a day, and now I have to decrease meat to 150 gr. a day in total, and also I have to limit the whole wheat products as well. Also, my urologist said that calcium from diet is fine, it gets absorbed different than calcium from supplements, so he told me to eliminate or limit calcium from supplements if I can. Unfortunately, he is not an obgyn and could not suggest a specific prenatal vitamin that has low calcium or no calcium. And then I have the problem with the constipation too, where the regular iron just gives me severe issues, but the chelated one seems to be fine. This is why so far I was taking a vitamin with no iron and took the chelated iron separately. I can also drink 4 glasses of milk, this is not an issue - I think this gives me the 1200mg of calcium a day from dietary sources. However, unfortunately, so far I have not been able to find such a vitamin that does not have excessive other ingredients (like the A or B vitamins) and has very low calcium and chelated iron/no iron. What would be your suggestion for the rest of my pregnancy?

Also, for breastfeeding later when I am done the pregnancy, is it mandatory to take vitamins? Maybe I can drink lots of milk and take iron from chelate and some folic acid separately and maybe this is enough for the baby? I heard that during breast feeding the vitamins are mostly for me and not the baby. So if I don't take them, would that harm the baby? I mean, is there something that I absolutely need to take when breastfeeding that the baby cannot do without and maybe the rest I can skip? I would really prefer to take no calcium in supplement form after the end of the pregnancy.

Answered by Dr. Timothy Raichle 4 hours later
Thank you for the followup. I do not have great access to your prior questions as far as knowing the background from prior questions.

We have had the prior conversation regarding chelated iron, so I will not go there again. As far as where you stand currently, I am going to be honest with you. I really think that you are 'over-thinking' the whole 'nutrition in pregnancy' issue. While I acknowledge that there are changes in your diet that will help with the kidney stone issue, as far as the micro-nutrients and their necessity during the pregnancy, you are splitting hairs over what is in the prenatal vitamin itself. I would not focus on every single ingredient as the vast majority carry little, if any, harm. If you are not anemic, then you do not need that much iron. If you are eating healthy foods, then you are getting these individual vitamins through your diet.

There are so many prenatal vitamins out there to choose from. They are all basically safe. Nexa makes a product that contains a stool softener that I would have you consider trying. Otherwise, I think you can take ANY multi-vitamin that is low in iron and you will be doing just fine. Even flintstones chewable vitamins is better than nothing. Try to begin to 'see the forest through the trees'. You are going to drive yourself crazy over these small details. There are many women who do not tolerate any prenatal vitamins and their children turn out just fine (assuming they eat a regular diet). You are obviously healthy and motivated.

With breast feeding, there is a need for increased calories and hydration. You can get both of these through a healthy diet alone. A multi-vitamin certainly seems healthy, but it is not critical. You will lose blood with the delivery, so an iron supplement, at the very least, will help you to get back to a normal energy level sooner after delivery.

I hope that this helps and good luck. Try to relax and enjoy the pregnancy!!
Above answer was peer-reviewed by
Follow-up: Pregnant. Have kidney stone. Getting constipated after taking materna. Suggest safe medicine 22 minutes later
Thanks Dr. Raichle, I can try Nexa. I also found Prefera OB, which seems like not a bad choice, so maybe I will try both and see which one I handle better.

Answered by Dr. Timothy Raichle 14 minutes later
I think that this is agreat idea!! I hope that one of these works for you. Please ask me directly if you have any questions in the future.

Good luck at delivery!
Above answer was peer-reviewed by
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