From the Guidelines
Your vitamin D level is low at 13 ng/mL, and you should start vitamin D supplementation to bring your level into the normal range of 30-100 ng/mL. For someone with your level of deficiency, I recommend taking vitamin D3 (cholecalciferol) 50,000 IU once weekly for 8 weeks, followed by a maintenance dose of 1,000-2,000 IU daily, as suggested by the NCCN task force report 1. Alternatively, you could take 5,000 IU daily for 8-12 weeks to replenish your stores, then switch to the maintenance dose.
- Take vitamin D supplements with food containing some fat to improve absorption.
- Additionally, try to get 15-30 minutes of sunlight exposure several times per week and include vitamin D-rich foods in your diet such as fatty fish, egg yolks, and fortified dairy products.
- Low vitamin D can lead to bone problems, muscle weakness, and has been associated with various health conditions including depression and reduced immune function.
- After 3 months of supplementation, you should have your vitamin D level rechecked to ensure it has improved to the normal range and adjust your maintenance dose if needed, as recommended by the USPSTF 1.
From the Research
Vitamin D Levels and Health Implications
- The given vitamin D level is 13 ng/mL, which is considered low according to various studies 2, 3, 4, 5.
- A level of 30 ng/mL is often considered the threshold for optimal vitamin D status, with levels below 20 ng/mL indicating deficiency and levels between 20-30 ng/mL indicating insufficiency 3, 5.
- Severe vitamin D deficiency can lead to nutritional rickets or osteomalacia, and low levels have also been linked to an increased risk of fractures, falls, and other health issues 2, 4.
Recommended Vitamin D Intake and Supplementation
- The recommended daily intake of vitamin D varies, but 600-800 IU/day is often suggested for adults, with higher doses recommended for older adults or those with certain medical conditions 2, 5.
- Vitamin D supplementation may be necessary for individuals with low levels, with doses ranging from 400-5000 IU/day depending on the individual's needs and health status 3, 6.
- It is essential to test serum 25-hydroxy-vitamin D (25OH-D) levels before prescribing vitamin D supplementation, but in some cases, moderate doses may be recommended without initial testing 6.
Health Risks Associated with Low Vitamin D Levels
- Low vitamin D levels have been linked to various health risks, including autoimmune disease, cancer, cardiovascular disease, depression, dementia, and infectious diseases 3, 4.
- Vitamin D plays a crucial role in immune function, with calcitriol stimulating innate immune responses and regulating the expression of genes involved in calcium metabolism, cell differentiation, apoptosis, and immunity 4.