Home Ingredients Aqua-D3® (Water-Dispersible Vitamin D3)
Immune SupportBone Health

Aqua-D3® (Water-Dispersible Vitamin D3)

Evidence Level
Moderate
2 Clinical Trials
3 Documented Benefits
3/5 Evidence Score

Aqua-D3 is a water-dispersible form of vitamin D3 (cholecalciferol), designed to mix into liquids and drinks. Vitamin D is an essential nutrient: it helps the gut absorb calcium, keeps blood calcium and phosphate at the levels bones need, and helps regulate immune function. None of the studies on this page tested Aqua-D3, so the evidence reflects vitamin D3 as a nutrient, and the idea that a water-dispersible form is absorbed better is not tested here. In a large pooled analysis of placebo-controlled trials, daily or weekly vitamin D modestly reduced acute respiratory infections, most in people starting very low. For bone, one trial in older women with low vitamin D found less hip bone loss with 1000 IU a day, while pooled analyses show little benefit from vitamin D alone in most adults.

Studied Dose No trial cited tested Aqua-D3. The benefits seen were with daily or weekly vitamin D (1000 IU of D3 a day in the bone trial), not large single doses. The adult upper limit is 4,000 IU a day unless a clinician advises otherwise.
Active Compound Vitamin D3 (cholecalciferol) in a water-dispersible form.

Benefits

Immune support

In a pooled analysis of individual data from 25 placebo-controlled trials (11,321 people aged 0 to 95), vitamin D modestly lowered the odds of having an acute respiratory infection (odds ratio 0.88). The effect was seen with daily or weekly doses, not large bolus doses, and was largest in people who started with very low vitamin D levels. None of the trials tested Aqua-D3.

Supported by Trial 1

Calcium absorption for normal bone mineralization

Vitamin D helps the gut absorb calcium and keeps blood calcium and phosphate at the levels needed for normal bone mineralization and bone remodeling. This is the established nutrient role of vitamin D in general; it is not a finding from a trial of Aqua-D3.

Supported by Trial 2, Trial 1

Bone density support with vitamin D3 when vitamin D status is low

Tested as plain vitamin D3, not Aqua-D3. In one placebo-controlled trial in 305 women aged 60 to 70 with low average starting vitamin D, 1000 IU a day for a year held hip bone density loss to 0.05% versus 0.60% on placebo; 400 IU did not. Pooled analyses of vitamin D alone show little or no bone density or fracture benefit in most adults. With calcium, hip fractures fell slightly: 1 fewer per 1000 older adults a year in the community.

Supported by Trial 2

Mechanism of action

1

Calcium absorption

Vitamin D is converted in the liver and kidney to its active form, calcitriol, which promotes calcium absorption in the gut and helps maintain the blood calcium and phosphate needed to build and maintain bone.

2

Immune modulation

Vitamin D helps modulate immune function and inflammation, and many tissues carry vitamin D receptors. This is a general nutrient role rather than a tested effect of this water-dispersible form.

Clinical trials

1
Vitamin D and acute respiratory infections: individual participant data analysis
PubMed

Systematic review and meta-analysis of individual participant data from 25 randomized, double-blind, placebo-controlled trials of vitamin D3 or D2; no trial used Aqua-D3. (Martineau et al. 2017, BMJ)

11,321 people aged 0 to 95 years, with individual data for 10,933 (96.6%).

Vitamin D reduced the odds of at least one acute respiratory infection overall (adjusted odds ratio 0.88, 95% CI 0.81 to 0.96). With daily or weekly dosing the odds ratio was 0.81, but bolus doses showed no benefit (0.97). Among daily or weekly users the effect was larger with baseline 25(OH)D below 25 nmol/L (0.30) than above it (0.75). Serious adverse events did not differ.

2
Daily vitamin D3 and hip bone loss in older women
PubMed

One-year randomized, double-blind, placebo-controlled trial of 400 IU or 1000 IU vitamin D3 a day, using plain vitamin D3 rather than Aqua-D3. (Macdonald et al. 2013, J Bone Miner Res)

305 women aged 60 to 70 in Scotland with a mean starting 25(OH)D of 33.8 nmol/L.

Hip bone density fell by 0.05% with 1000 IU a day, against 0.57% with 400 IU and 0.60% with placebo. Bone turnover markers did not change.

Side effects and drug interactions

Common Potential side effects

Generally well tolerated at usual doses; in the respiratory infection analysis, serious adverse events did not differ from placebo.
Very high intakes over time can raise blood calcium; the adult upper limit is 4,000 IU a day unless a clinician advises more.
Having your vitamin D level checked can help guide dosing.

Important Drug interactions

Thiazide diuretics: these reduce calcium loss in urine, and combined with vitamin D they might lead to high blood calcium, especially in older adults or people with kidney problems.
Orlistat, statins and steroid medicines can interact with vitamin D or affect vitamin D levels; discuss your intake with your clinician.

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Frequently asked questions about Aqua-D3® (Water-Dispersible Vitamin D3)

What is Aqua-D3?

Aqua-D3 is a water-dispersible form of vitamin D3 (cholecalciferol), designed to mix into liquids and drinks. Vitamin D is an essential nutrient: it helps the gut absorb calcium, keeps blood calcium and phosphate at the levels bones need, and helps regulate immune function.

What is Aqua-D3 used for?

Aqua-D3 is researched primarily for Immune Support and Bone Health. In a pooled analysis of individual data from 25 placebo-controlled trials (11,321 people aged 0 to 95), vitamin D modestly lowered the odds of having an acute respiratory infection (odds ratio 0.88).

What is the recommended dosage of Aqua-D3?

No trial cited tested Aqua-D3. The benefits seen were with daily or weekly vitamin D (1000 IU of D3 a day in the bone trial), not large single doses. The adult upper limit is 4,000 IU a day unless a clinician advises otherwise. Always follow the product label and check with a healthcare provider for personal advice.

Is Aqua-D3 safe, and does it have side effects?

Side effects and cautions reported for Aqua-D3 include: Generally well tolerated at usual doses; in the respiratory infection analysis, serious adverse events did not differ from placebo. Very high intakes over time can raise blood calcium; the adult upper limit is 4,000 IU a day unless a clinician advises more. It may also interact with some medications. Aqua-D3 is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Aqua-D3 interact with any medications?

Possible interactions include: Thiazide diuretics: these reduce calcium loss in urine, and combined with vitamin D they might lead to high blood calcium, especially in older adults or people with kidney problems. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Aqua-D3?

NutraSmarts rates the evidence for Aqua-D3 as Moderate (3 out of 5). It is backed by 2 study summaries and 5 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(5 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Martineau AR, Jolliffe DA, Hooper RL, Greenberg L, Aloia JF, Bergman P, Dubnov-Raz G, Esposito S, Ganmaa D, Ginde AA, Goodall EC, Grant CC, Griffiths CJ, Janssens W, Laaksi I, Manaseki-Holland S, Mauger D, Murdoch DR, Neale R, Rees JR, Simpson S Jr, Stelmach I, Kumar GT, Urashima M, Camargo CA Jr. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. BMJ. 2017;356:i6583. doi: 10.1136/bmj.i6583.PubMedUsed to support: Individual participant data meta-analysis of 25 trials and 11,321 participants: modest overall reduction in acute respiratory tract infection (adjusted OR 0.88), with benefit from daily or weekly dosing (0.81), the largest effect in people with baseline 25(OH)D below 25 nmol/L, and no significant benefit with bolus dosing. It does not name or test Aqua-D3 and measured no skeletal outcome.
  2. Macdonald HM, Wood AD, Aucott LS, Black AJ, Fraser WD, Mavroeidi A, Reid DM, Secombes KR, Simpson WG, Thies F. Hip bone loss is attenuated with 1000 IU but not 400 IU daily vitamin D3: a 1-year double-blind RCT in postmenopausal women. J Bone Miner Res. 2013;28(10):2202-13. doi: 10.1002/jbmr.1959.PubMedUsed to support: One-year double-blind placebo-controlled trial in 305 postmenopausal women aged 60 to 70 in Scotland, with mean baseline 25(OH)D of 33.8 nmol/L. Mean hip BMD loss was 0.05% with 1000 IU/day vitamin D3, against 0.57% with 400 IU and 0.60% with placebo. Bone turnover markers did not change. It tested plain vitamin D3, not Aqua-D3.
  3. Reid IR, Bolland MJ, Grey A. Effects of vitamin D supplements on bone mineral density: a systematic review and meta-analysis. Lancet. 2014;383(9912):146-55. doi: 10.1016/S0140-6736(13)61647-5.PubMedUsed to support: Pooled analysis of 23 randomized trials (4082 participants, 92% women, average age 59) in which the groups differed only in vitamin D (D3 or D2) content. It found a small femoral neck BMD benefit (weighted mean difference 0.8%, 95% CI 0.2 to 1.4) with substantial heterogeneity, and no effect at any other site, including the total hip. The authors concluded that widespread use for osteoporosis prevention in community-dwelling adults without specific risk factors for vitamin D deficiency seems to be inappropriate. It did not test Aqua-D3.
  4. Avenell A, Mak JC, O'Connell D. Vitamin D and vitamin D analogues for preventing fractures in post-menopausal women and older men. Cochrane Database Syst Rev. 2014;2014(4):CD000227. doi: 10.1002/14651858.CD000227.pub4.PubMedUsed to support: Review of 53 trials and 91,791 participants, including 22 trials of the analogues calcitriol or alfacalcidol. Vitamin D alone was unlikely to prevent hip fracture (RR 1.12, 95% CI 0.98 to 1.29) or any new fracture (RR 1.03, 0.96 to 1.11). Vitamin D plus calcium gave a small reduction in hip fracture (RR 0.84, 0.74 to 0.96), which equates to about 1 fewer hip fracture per 1000 community-dwelling older adults per year (95% CI 0 to 2), and in any fracture (RR 0.95, 0.90 to 0.99). It did not test Aqua-D3.
  5. Office of Dietary Supplements, National Institutes of Health. Vitamin D: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. 2025;Updated June 27, 2025..SourceUsed to support: Not PubMed-indexed; official NIH fact sheet. States that vitamin D promotes calcium absorption in the gut and keeps blood calcium and phosphate adequate for normal bone mineralization, that it helps modulate immune function, that many tissues have vitamin D receptors, that the adult upper limit is 4,000 IU a day, and that thiazide diuretics combined with vitamin D might lead to high blood calcium.