Dieters lost 5 more pounds if achieved more than 32 ng of vitamin D – RCT March 2014

Vitamin D3 supplementation during weight loss: a double-blind randomized controlled trial.

Am J Clin Nutr. 2014 Mar 12.
Mason C1, Xiao L, Imayama I, Duggan C, Wang CY, Korde L, McTiernan A.
Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA (CM, LX, II, CD, C-YW, LK, and AM), and the Department of Epidemiology, School of Public Health (AM), the Department of Biostatistics, School of Public Health (CYW), and the Department of Medicine (LK), University of Washington, Seattle, WA.

BACKGROUND: Vitamin D deficiency is associated with obesity; whether repletion supports weight loss and changes obesity-related biomarkers is unknown.

OBJECTIVE: We compared 12 mo of vitamin D3 supplementation with placebo on weight, body composition, insulin, and C-reactive protein (CRP) in postmenopausal women in a weight-loss intervention.

DESIGN:
A total of 218 overweight/obese women (50-75 y of age) with serum 25-hydroxyvitamin D [25(OH)D] ≥10 ng/mL but <32 ng/mL were randomly assigned to weight loss + 2000 IU oral vitamin D3/d or weight loss + daily placebo. The weight-loss intervention included a reduced-calorie diet (10% weight loss goal) and 225 min/wk of moderate-to-vigorous aerobic activity. Mean 12-mo changes in weight, body composition, serum insulin, CRP, and 25(OH)D were compared between groups (intent-to-treat) by using generalized estimating equations.

RESULTS:
A total of 86% of participants completed the 12-mo measurements. The mean (95% CI) change in 25(OH)D was 13.6 (11.6, 15.4) ng/mL in the vitamin D3 arm compared with -1.3 (-2.6, -0.3) ng/mL in the placebo arm (P < 0.0001). Changes in weight [-7.1 (-8.7, -5.7) compared with -7.4 (-8.1, -5.4) kg], body mass index (in kg/m2: both -2.8), waist circumference [-4.9 (-6.7, -2.9) compared with -4.5 (-5.6, -2.6) cm], percentage body fat [-4.1 (-4.9, -2.9) compared with -3.5 (-4.5, -2.5)], trunk fat [-4.1 (-4.7, -3.0) compared with -3.7 (-4.3, -2.9) kg], insulin [-2.5 (-3.4, -1.7) compared with -2.4 (-3.3, -1.4) μU/mL], and CRP [-0.9 (-1.2, -0.6) compared with -0.79 (-0.9, -0.4) mg/mL] were similar between groups (all P > 0.05).

Compared with women who achieved 25(OH)D <32 ng/mL, women randomly assigned to vitamin D who became replete (ie, 25(OH)D ≥32 ng/mL)

• lost more weight [-8.8 (-11.1, -6.9) compared with -5.6 (-7.2, -5.0) kg; P = 0.05],
• waist circumference [-6.6 (-9.3, -4.3) compared with -2.5 (-4.6, -2.0) cm; P = 0.02], and
• percentage body fat [-4.7 (-6.1, -3.5) compared with -2.6 (-3.9, -2.2); P = 0.04].

Among women with complete pill counts (97% adherence), the mean decrease in CRP was 1.18 mg/mL (46%) in the vitamin D arm compared with 0.46 mg/mL (25%) in the placebo arm (P = 0.03).

CONCLUSIONS:
Vitamin D3 supplementation during weight loss did not increase weight loss or associated factors compared with placebo; however, women who became replete experienced greater improvements. This trial was registered at clinicaltrials.gov as NCT01240213.
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Google Scholar found that this paper was cited 159 times as of Nov 2023

• Is Vitamin D Supplementation Useful for Weight Loss Programs? A Systematic Review and Meta-Analysis of Randomized Controlled Trials July 2019 FREE PDF
• Association of Vitamin D and Obesity: An Overview June 2019 FREE PDF
• Effect of serum vitamin D levels on weight loss in obese patients doing aerobic exercises: A retrospective study - 2020
• Can lack of vitamin D cause weight gain? - June 2020

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Summary and comments by VitaminDWiki

Postmenopausal overweight women were on dietary restriction plan for 1 year, with exercise
Some of the women had 2,000 IU of vitamin D added to their diet
Any woman who achieved > 32 ng of vitamin D ended up losing an addtional 5 lbs of weight
Comments by VitaminDWiki

1. A majority of people who are overweight need > 2,000 IU to achieve > 32 ng of vitamin D
2. A Loading dose of 200,000 to 400,000 IU reduces by about 3 months the time to get to > 32 ng

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See also VitaminDWiki

• Weight loss and Vitamin D - many studies
• This Common Vitamin Doubles Weight Loss– July 2019
• The Vitamin D Diet – book Sept 2012
• Vitamin D may block the obesity gene (FTO) – Jan 2014
• Obese lost more weight on diet if added 50,000 IU of vitamin D weekly – many RCTs
• Weight loss and Vitamin D, Calcium, and Magnesium
• Vitamins To Speed Up Metabolism And Aid Weight Loss – May 2011
• Overview Metabolic Syndrome and vitamin D
• Obese need 2.5 IU of vitamin D per kg to increase 1 ng (about 3.4 X more) – RCT Sept 2013
  Example: Typical 100 kg (250 lbs) woman needs 2,500 IU to increase vitamin D by 10 ng, 5,000 IU to increase by 10 ng
  Please note that this is typical: An individual may need anywhere from 2X less to 2X more
• Now we know why vitamin D is not advertised for weight loss it was patented
• Women can lose weight with vitamin D - Nov 2010 2000 IU
• Vitamin D is sometimes a diet pill - VitaminDWiki Blog post
• Weight loss by UV or Vitamin D
• Overview Women and Vitamin D
• Need 40 to 80 ng of vitamin D to lose weight – Colgan Sept 2013
• Overweight and obese lost 12 lbs with vitamin D in 6 months– RCT May 2015

Overview Obesity and Vitamin D contains the following summary

• FACT: People who are obese have less vitamin D in their blood
• FACT: Obese need a higher dose of vitamin D to get to the same level of vit D
• FACT: When obese people lose weight the vitamin D level in their blood increases
• FACT: Adding Calcium, perhaps in the form of fortified milk, often reduces weight
• FACT: [https://clinicaltrials.gov||204 trials for vitamin D intervention of obesity as of April 2025]
• FACT: Less weight gain by senior women with > 30 ng of vitamin D
• FACT: Dieters lost additional 5 lbs if vitamin D supplementation got them above 32 ng - RCT
• FACT: Obese lost 3X more weight by adding $10 of Vitamin D
• FACT: Those with darker skins were more likely to be obese Sept 2014
• OBSERVATION: Low Vitamin D while pregnancy ==> more obese child and adult
• OBSERVATION: Many mammals had evolved to add fat and vitamin D in the autumn
  • and lose both in the Spring - unfortunately humans have forgotten to lose the fat in the Spring
• SPECULATION: Low vitamin D might be one of the causes of obesity – several studies
• SUGGESTION: Probably need more than 4,000 IU to lose weight if very low on vitamin D due to
    risk factors such as overweight, age, dark skin, live far from equator,shut-in, etc.
• Obesity category has 446 items

See also: Weight loss and Vitamin D - many studies   Child Obesity and Vitamin D - many studies   Obesity, Virus, and Vitamin D - many studies
Obese need more Vitamin D

• Normal weight     Obese     (50 ng = 125 nanomole)

Click here for 2014 study