Calcium increased risk of side effects in trials (no problems with just Vitamin D) – meta-analysis

Created December 2017

Noncalcemic adverse effects and withdrawals in randomized controlled trials of long-term vitamin D2 or D3 supplementation: a systematic review and meta-analysis.

Nutr Rev. 2017 Nov 30. doi: 10.1093/nutrit/nux059. [Epub ahead of print]

Malihi Z1, Wu Z1, Mm Lawes C1, Scragg R1.

School of Population Health, University of Auckland, Auckland, New Zealand.

Getting more than about 1 gram of calcium supplement causes many health problems - with or without vitamin D The Institute of Medicine in 2010 mistakenly said 4 grams was OK - even with Vitamin D * * Calcium and Vitamin D category listing has items along with related searches** * Is a health problem associated with Low vitamin D, Low Magnesium, or too much Calcium – Jan 2016 * Calcium supplementation associated with 3.9X increase risk of atrial fibrillation – June 2015 * Calcium Essential to Limit Osteoporosis but Avoid Excess, Say Europeans - Nov 2017 * Hypercalcemia can result from excess Vitamin D (if not reduce Ca or increase water) Oct 2016 * Risk of Ischemic Stroke doubles if take more than 1 gram of Calcium daily for years – May 2017 * Vitamin D response reduced if taken with Calcium – meta-analysis Oct 2015 If you feel that you must take > .75 gram of Calcium, be sure to take Vitamin K to keep it out of your arteries and drink lots of water to flush it out of your system

CONTEXT:

Recent randomized controlled trials (RCTs) provide evidence for a possible beneficial impact of vitamin D supplementation on health outcomes beyond bone health, but there are few reviews of noncalcemic adverse effects from long-term supplementation.

OBJECTIVE:

The aims of this systematic review of vitamin D supplementation in RCTs were as follows: to determine whether all adverse effects, when combined, are reported equally between treatment arms; to identify the most common noncalcemic adverse effects reported; and to ascertain whether withdrawal rates, as a marker of clinical adverse effects, differ between treatment arms.

DATA SOURCES:

The MEDLINE Ovid, Embase, and Cochrane Library databases were searched systematically up to May 2016.

STUDY SELECTION:

Randomized controlled trials that met the following criteria were selected: administered vitamin D2 or D3 supplements for a minimum supplementation or follow-up period of 24 weeks, had a placebo/control group, and were conducted among adults (≥ 18 y).

DATA EXTRACTION:

Two researchers independently screened studies for eligibility, extracted data, and carried out quality assessment of selected studies. A total of 128 studies with 52 297 participants were identified. A random-effects model was used to calculate risk ratios in a meta-analysis.

RESULTS:

  • Long-term vitamin D2 or D3 supplementation, compared with placebo, did not increase all adverse effects, when combined, as reported in 62 studies with 19 389 participants (relative risk [RR] = 0.97; 95%CI, 0.92-1.02).

  • Vitamin D also did not increase the risk of the most common noncalcemic adverse effects:

    • gastrointestinal symptoms were reported in 27 studies with 9189 participants (RR = 1.01; 95%CI, 0.87-1.17), and
    • dermatological symptoms were reported in 8 studies with 1695 participants (RR = 1.33; 95%CI, 0.82-2.15).

  • Vitamin D did not increase withdrawals from 123 studies with 41 861 participants (RR = 1.03; 95%CI, 0.96-1.09).

  • However, participants given vitamin D were more likely to report withdrawals than those given placebo in studies in which calcium was given in both arms (RR = 1.16; 95%CI, 1.02-1.33) when compared with participants in studies in which calcium was not given in either arm (RR = 1.00; 95%CI, 0.95-1.06; P for interaction = 0.009).

CONCLUSIONS:

Overall, these findings suggest that vitamin D, by itself, does not increase the risk of noncalcemic adverse effects.

PMID: 29202186 DOI: 10.1093/nutrit/nux059

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Tags: Calcium Meta-analysis