It is recognized obese individuals tend to have lower levels of vitamin D. This could be due to a variety of factors such as decreased absorption, eating choices, or sun exposure. However, current study results are conflicting about whether vitamin D can contribute to weight loss. In many studies, vitamin D is referred to as 25-hydroxyvitamin D or 25(OH)D, which is the converted form of vitamin D found in the body.
Results of vitamin D studies relating to weight are mixed.
Journal of Women's Health Care, 2012
A 2012 longitudinal study followed women 65 years of age and older for 4.5 years. The women were weighed and had their vitamin D levels tested at the beginning and end of the study. The results of the study reported women whose vitamin D levels were higher at the end of the study had gained a smaller amount of weight over time.
Nutrition Journal, 2012
Additionally, a 2012 study supplemented vitamin D as cholecalciferol or a placebo to 77 overweight participants for 12 weeks. Upon completion, the study reported a decrease in fat mass in the vitamin D supplement group. However, neither group demonstrated a change in body weight and waist circumference.
Clinical Nutrition, 2016
In contrast, a 2016 study conducted on obese individuals with type 2 diabetes found no relationship between vitamin D supplementation for one year and weight, fat mass, or waist circumference.
American Journal of Clinical Nutrition, 2014
Finally, a 2014 study published in the American Journal of Clinical Nutrition studied the effects of a year long supplementation of vitamin D paired with a diet and exercise regimen in 218 postmenopausal women. The results of the study reported although vitamin D supplementation did not increase weight loss, women whose vitamin D stores became replenished, as defined by levels 25(OH)D greater than 32 ng/mL, experienced greater weight loss results.
It is clear from the contrasting result reported in the studies above more research is needed to determine how vitamin D may influence weight loss.
Vitamin D in Daily Life
How can the above studies be applied to daily life? Currently, there are no evidence-based recommendations for vitamin D supplementation for weight loss. However, as demonstrated by the 2014 study, ensuring your vitamin D levels are adequate may help your weight loss goals.
A 2011 study reported nearly 42 percent of Americans are vitamin D deficient with more prevalence in people with no college education, who were obese, had a poor health status, hypertension, low high-density lipoprotein cholesterol level, or who were not consuming milk daily. A vitamin D deficiency was defined as serum 25(OH)D levels less than 20 ng/mL.
Vitamin D Recommendations
Ensuring you are getting enough vitamin D can help correct a common deficiency and could potentially help in weight loss. A circulating level of 25(OH)D of 30 ng/mL is recommended by The American Journal of Clinical Nutrition for optimum health. Many people can achieve this level by practicing one of the following:
- Consuming 800-1000 IU vitamin D3 daily through food high in vitamin D
- One cup of fortified milk provides 115 to 124IU.
- Three ounces of salmon provides 447IU.
- One cup of fortified orange juice provides 137IU.
- One tablespoon of cod liver oil provides 1,360IU.
- Spending 10 to 15 minutes in the sun
- The Endocrine Society recommends taking a vitamin D supplement of 1,500 to 2,000 IU/day of vitamin D
Receiving enough vitamin D can help your body in many ways and could potentially help in weight loss. However, use caution as the upper limit for vitamin D is 4,000IU for those ages nine and up.
Vitamin D and Your Waistline
Current research is inconclusive whether vitamin D can aid in weight loss. Many factors can impact weight loss, which presents the need for more studies in this area. However, ensuring you are replenishing your vitamin D stores through diet, sunlight, or supplement can't hurt and may even help your weight loss efforts.