What is the recommended sunlight exposure for an infant to produce vitamin D?

From the Guidelines

Infants should not rely on sunlight exposure to get vitamin D, instead, they should receive vitamin D supplementation to maintain adequate serum vitamin D concentration. According to the American Academy of Pediatrics, as stated in the study published in Pediatrics in 2005 1, all infants consuming less than 28 ounces of commercial infant formula per day should receive an oral supplement of vitamin D 400 IU per day, beginning at hospital discharge and throughout breastfeeding. This recommendation applies to both exclusively and partially breastfed infants. Some key points to consider are:

• Vitamin D deficiency or insufficiency and rickets has increased in all infants as a result of decreased sunlight exposure secondary to changes in lifestyle, dress habits, and use of topical sunscreen preparations 1
• Direct sun exposure is not recommended for infants, especially those under 6 months, due to the risk of sunburn and skin damage
• Infant skin is thin and vulnerable, and sunscreen is not approved for babies younger than 6 months
• Vitamin D is essential for calcium absorption and bone development, and deficiency can lead to rickets, a condition causing soft, weak bones The risks of sun exposure outweigh the benefits for infants, making supplementation the safer choice, as recommended by the study 1.

From the Research

Sunlight Exposure for Infants to Get Vitamin D

• The American Academy of Pediatrics recommends that infants receive 400 IU of vitamin D per day, which can be achieved through a combination of dietary sources and sunlight exposure 2.
• A study found that a minimum of 30 minutes of weekly afternoon sunlight exposure, between 10 am and 3 pm, over 40% of the body surface area, was estimated to be required to achieve sufficient vitamin D levels in infants by 6 months of age 3.
• Another study found that oral vitamin D3 supplementation was more efficacious than sunlight exposure in achieving vitamin D sufficiency in breastfed infants during the first 6 months of life, due to better compliance 4.
• Sunlight exposure has been shown to provide protection against a wide variety of diseases, including vitamin D deficiency, and avoiding sunlight may influence the initiation and progression of some diseases 5.
• A study found that vitamin D deficiency was widespread in early post-partum breastfeeding mothers and infants, and declined to one in eight infants at 52 weeks due mostly to sunshine exposure 6.

Key Findings

• Cumulative sun index correlated positively with infant's serum 25(OH)D level at 6 months of age 3.
• Increment in afternoon sun index by 1 unit increased the serum 25(OH)D level by 1.07 ng/mL 3.
• Oral vitamin D3 supplementation increased the proportion of infants with vitamin D sufficiency from 10.8% to 35.1% 4.
• Sunlight exposure is an important factor in achieving vitamin D sufficiency in infants, especially when dietary sources are limited 6, 2.

Considerations

• The American Academy of Pediatrics recommends keeping infants out of direct sunlight, but decreased sunlight exposure may increase children's risk of vitamin D deficiency 2.
• Avoiding sunlight, coupled with the inclination towards consuming supplements, is becoming the primary choice to obtain vitamin D, but the expected benefits of vitamin D supplements are minimized by the potential risk of cardiovascular events and beyond 5.